linux/sound/core/timer.c

2508 lines
62 KiB

ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 15:45:31 +02:00
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 15:45:31 +02:00
ALSA: timer: Fix incorrectly assigned timer instance The clean up commit 41672c0c24a6 ("ALSA: timer: Simplify error path in snd_timer_open()") unified the error handling code paths with the standard goto, but it introduced a subtle bug: the timer instance is stored in snd_timer_open() incorrectly even if it returns an error. This may eventually lead to UAF, as spotted by fuzzer. The culprit is the snd_timer_open() code checks the SNDRV_TIMER_IFLG_EXCLUSIVE flag with the common variable timeri. This variable is supposed to be the newly created instance, but we (ab-)used it for a temporary check before the actual creation of a timer instance. After that point, there is another check for the max number of instances, and it bails out if over the threshold. Before the refactoring above, it worked fine because the code returned directly from that point. After the refactoring, however, it jumps to the unified error path that stores the timeri variable in return -- even if it returns an error. Unfortunately this stored value is kept in the caller side (snd_timer_user_tselect()) in tu->timeri. This causes inconsistency later, as if the timer was successfully assigned. In this patch, we fix it by not re-using timeri variable but a temporary variable for testing the exclusive connection, so timeri remains NULL at that point. Fixes: 41672c0c24a6 ("ALSA: timer: Simplify error path in snd_timer_open()") Reported-and-tested-by: Tristan Madani <tristmd@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191106165547.23518-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-11-06 17:55:47 +01:00
ALSA: timer: Fix incorrectly assigned timer instance The clean up commit 41672c0c24a6 ("ALSA: timer: Simplify error path in snd_timer_open()") unified the error handling code paths with the standard goto, but it introduced a subtle bug: the timer instance is stored in snd_timer_open() incorrectly even if it returns an error. This may eventually lead to UAF, as spotted by fuzzer. The culprit is the snd_timer_open() code checks the SNDRV_TIMER_IFLG_EXCLUSIVE flag with the common variable timeri. This variable is supposed to be the newly created instance, but we (ab-)used it for a temporary check before the actual creation of a timer instance. After that point, there is another check for the max number of instances, and it bails out if over the threshold. Before the refactoring above, it worked fine because the code returned directly from that point. After the refactoring, however, it jumps to the unified error path that stores the timeri variable in return -- even if it returns an error. Unfortunately this stored value is kept in the caller side (snd_timer_user_tselect()) in tu->timeri. This causes inconsistency later, as if the timer was successfully assigned. In this patch, we fix it by not re-using timeri variable but a temporary variable for testing the exclusive connection, so timeri remains NULL at that point. Fixes: 41672c0c24a6 ("ALSA: timer: Simplify error path in snd_timer_open()") Reported-and-tested-by: Tristan Madani <tristmd@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191106165547.23518-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-11-06 17:55:47 +01:00
ALSA: timer: fix NULL pointer dereference on memory allocation failure I hit this with syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff88011278d600 task.stack: ffff8801120c0000 RIP: 0010:[<ffffffff82c8ba07>] [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP: 0018:ffff8801120c7a60 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048 RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790 R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980 R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286 FS: 00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0 Stack: ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0 ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000 ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0 Call Trace: [<ffffffff82c81ab1>] snd_timer_start1+0x331/0x670 [<ffffffff82c85bfd>] snd_timer_start+0x5d/0xa0 [<ffffffff82c8795e>] snd_timer_user_ioctl+0x88e/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff8132762f>] ? put_prev_entity+0x108f/0x21a0 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff813510af>] ? cpuacct_account_field+0x12f/0x1a0 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46 RIP [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP <ffff8801120c7a60> ---[ end trace 5955b08db7f2b029 ]--- This can happen if snd_hrtimer_open() fails to allocate memory and returns an error, which is currently not checked by snd_timer_open(): ioctl(SNDRV_TIMER_IOCTL_SELECT) - snd_timer_user_tselect() - snd_timer_close() - snd_hrtimer_close() - (struct snd_timer *) t->private_data = NULL - snd_timer_open() - snd_hrtimer_open() - kzalloc() fails; t->private_data is still NULL ioctl(SNDRV_TIMER_IOCTL_START) - snd_timer_user_start() - snd_timer_start() - snd_timer_start1() - snd_hrtimer_start() - t->private_data == NULL // boom Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29 00:33:51 +02:00
ALSA: timer: fix NULL pointer dereference on memory allocation failure I hit this with syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff88011278d600 task.stack: ffff8801120c0000 RIP: 0010:[<ffffffff82c8ba07>] [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP: 0018:ffff8801120c7a60 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048 RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790 R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980 R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286 FS: 00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0 Stack: ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0 ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000 ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0 Call Trace: [<ffffffff82c81ab1>] snd_timer_start1+0x331/0x670 [<ffffffff82c85bfd>] snd_timer_start+0x5d/0xa0 [<ffffffff82c8795e>] snd_timer_user_ioctl+0x88e/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff8132762f>] ? put_prev_entity+0x108f/0x21a0 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff813510af>] ? cpuacct_account_field+0x12f/0x1a0 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46 RIP [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP <ffff8801120c7a60> ---[ end trace 5955b08db7f2b029 ]--- This can happen if snd_hrtimer_open() fails to allocate memory and returns an error, which is currently not checked by snd_timer_open(): ioctl(SNDRV_TIMER_IOCTL_SELECT) - snd_timer_user_tselect() - snd_timer_close() - snd_hrtimer_close() - (struct snd_timer *) t->private_data = NULL - snd_timer_open() - snd_hrtimer_open() - kzalloc() fails; t->private_data is still NULL ioctl(SNDRV_TIMER_IOCTL_START) - snd_timer_user_start() - snd_timer_start() - snd_timer_start1() - snd_hrtimer_start() - t->private_data == NULL // boom Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29 00:33:51 +02:00
ALSA: timer: fix NULL pointer dereference on memory allocation failure I hit this with syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff88011278d600 task.stack: ffff8801120c0000 RIP: 0010:[<ffffffff82c8ba07>] [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP: 0018:ffff8801120c7a60 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048 RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790 R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980 R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286 FS: 00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0 Stack: ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0 ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000 ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0 Call Trace: [<ffffffff82c81ab1>] snd_timer_start1+0x331/0x670 [<ffffffff82c85bfd>] snd_timer_start+0x5d/0xa0 [<ffffffff82c8795e>] snd_timer_user_ioctl+0x88e/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff8132762f>] ? put_prev_entity+0x108f/0x21a0 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff813510af>] ? cpuacct_account_field+0x12f/0x1a0 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46 RIP [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP <ffff8801120c7a60> ---[ end trace 5955b08db7f2b029 ]--- This can happen if snd_hrtimer_open() fails to allocate memory and returns an error, which is currently not checked by snd_timer_open(): ioctl(SNDRV_TIMER_IOCTL_SELECT) - snd_timer_user_tselect() - snd_timer_close() - snd_hrtimer_close() - (struct snd_timer *) t->private_data = NULL - snd_timer_open() - snd_hrtimer_open() - kzalloc() fails; t->private_data is still NULL ioctl(SNDRV_TIMER_IOCTL_START) - snd_timer_user_start() - snd_timer_start() - snd_timer_start1() - snd_hrtimer_start() - t->private_data == NULL // boom Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29 00:33:51 +02:00
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 15:45:31 +02:00
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 15:45:31 +02:00
ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE I got this: divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #189 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff8801120a9580 task.stack: ffff8801120b0000 RIP: 0010:[<ffffffff82c8bd9a>] [<ffffffff82c8bd9a>] snd_hrtimer_callback+0x1da/0x3f0 RSP: 0018:ffff88011aa87da8 EFLAGS: 00010006 RAX: 0000000000004f76 RBX: ffff880112655e88 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff880112655ea0 RDI: 0000000000000001 RBP: ffff88011aa87e00 R08: ffff88013fff905c R09: ffff88013fff9048 R10: ffff88013fff9050 R11: 00000001050a7b8c R12: ffff880114778a00 R13: ffff880114778ab4 R14: ffff880114778b30 R15: 0000000000000000 FS: 00007f071647c700(0000) GS:ffff88011aa80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 0000000112021000 CR4: 00000000000006e0 Stack: 0000000000000000 ffff880114778ab8 ffff880112655ea0 0000000000004f76 ffff880112655ec8 ffff880112655e80 ffff880112655e88 ffff88011aa98fc0 00000000b97ccf2b dffffc0000000000 ffff88011aa98fc0 ffff88011aa87ef0 Call Trace: <IRQ> [<ffffffff813abce7>] __hrtimer_run_queues+0x347/0xa00 [<ffffffff82c8bbc0>] ? snd_hrtimer_close+0x130/0x130 [<ffffffff813ab9a0>] ? retrigger_next_event+0x1b0/0x1b0 [<ffffffff813ae1a6>] ? hrtimer_interrupt+0x136/0x4b0 [<ffffffff813ae220>] hrtimer_interrupt+0x1b0/0x4b0 [<ffffffff8120f91e>] local_apic_timer_interrupt+0x6e/0xf0 [<ffffffff81227ad3>] ? kvm_guest_apic_eoi_write+0x13/0xc0 [<ffffffff83c35086>] smp_apic_timer_interrupt+0x76/0xa0 [<ffffffff83c3416c>] apic_timer_interrupt+0x8c/0xa0 <EOI> [<ffffffff83c3239c>] ? _raw_spin_unlock_irqrestore+0x2c/0x60 [<ffffffff82c8185d>] snd_timer_start1+0xdd/0x670 [<ffffffff82c87015>] snd_timer_continue+0x45/0x80 [<ffffffff82c88100>] snd_timer_user_ioctl+0x1030/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff815aa4f8>] ? handle_mm_fault+0xbc8/0x27f0 [<ffffffff815a9930>] ? __pmd_alloc+0x370/0x370 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: e8 fc 42 7b fe 8b 0d 06 8a 50 03 49 0f af cf 48 85 c9 0f 88 7c 01 00 00 48 89 4d a8 e8 e0 42 7b fe 48 8b 45 c0 48 8b 4d a8 48 99 <48> f7 f9 49 01 c7 e8 cb 42 7b fe 48 8b 55 d0 48 b8 00 00 00 00 RIP [<ffffffff82c8bd9a>] snd_hrtimer_callback+0x1da/0x3f0 RSP <ffff88011aa87da8> ---[ end trace 6aa380f756a21074 ]--- The problem happens when you call ioctl(SNDRV_TIMER_IOCTL_CONTINUE) on a completely new/unused timer -- it will have ->sticks == 0, which causes a divide by 0 in snd_hrtimer_callback(). Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-29 00:33:50 +02:00
*: convert stream-like files from nonseekable_open -> stream_open Using scripts/coccinelle/api/stream_open.cocci added in 10dce8af3422 ("fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock"), search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Among cases converted 14 were potentially vulnerable to read vs write deadlock (see details in 10dce8af3422): drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/infiniband/core/user_mad.c:988:1-17: ERROR: umad_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/misc/uinput.c:401:1-17: ERROR: uinput_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. and the rest were just safe to convert to stream_open because their read and write do not use ppos at all and corresponding file_operations do not have methods that assume @offset file access(*): arch/powerpc/platforms/52xx/mpc52xx_gpt.c:631:8-24: WARNING: mpc52xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/um/drivers/harddog_kern.c:88:8-24: WARNING: harddog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/x86/kernel/cpu/microcode/core.c:430:33-49: WARNING: microcode_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ds1620.c:215:8-24: WARNING: ds1620_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/dtlk.c:301:1-17: WARNING: dtlk_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ipmi/ipmi_watchdog.c:840:9-25: WARNING: ipmi_wdog_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/pcmcia/scr24x_cs.c:95:8-24: WARNING: scr24x_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/tb0219.c:246:9-25: WARNING: tb0219_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/firewire/nosy.c:306:8-24: WARNING: nosy_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/fschmd.c:840:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/w83793.c:1344:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucma.c:1747:8-24: WARNING: ucma_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucm.c:1178:8-24: WARNING: ucm_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/uverbs_main.c:1086:8-24: WARNING: uverbs_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/input/joydev.c:282:1-17: WARNING: joydev_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/pci/switch/switchtec.c:393:1-17: WARNING: switchtec_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/platform/chrome/cros_ec_debugfs.c:135:8-24: WARNING: cros_ec_console_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-ds1374.c:470:9-25: WARNING: ds1374_wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-m41t80.c:805:9-25: WARNING: wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/tape_char.c:293:2-18: WARNING: tape_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/zcore.c:194:8-24: WARNING: zcore_reipl_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/crypto/zcrypt_api.c:528:8-24: WARNING: zcrypt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/spi/spidev.c:594:1-17: WARNING: spidev_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/staging/pi433/pi433_if.c:974:1-17: WARNING: pi433_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/acquirewdt.c:203:8-24: WARNING: acq_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/advantechwdt.c:202:8-24: WARNING: advwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim1535_wdt.c:252:8-24: WARNING: ali_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim7101_wdt.c:217:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ar7_wdt.c:166:8-24: WARNING: ar7_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/at91rm9200_wdt.c:113:8-24: WARNING: at91wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ath79_wdt.c:135:8-24: WARNING: ath79_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/bcm63xx_wdt.c:119:8-24: WARNING: bcm63xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpu5wdt.c:143:8-24: WARNING: cpu5wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpwd.c:397:8-24: WARNING: cpwd_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/eurotechwdt.c:319:8-24: WARNING: eurwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/f71808e_wdt.c:528:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/gef_wdt.c:232:8-24: WARNING: gef_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/geodewdt.c:95:8-24: WARNING: geodewdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ib700wdt.c:241:8-24: WARNING: ibwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ibmasr.c:326:8-24: WARNING: asr_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/indydog.c:80:8-24: WARNING: indydog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/intel_scu_watchdog.c:307:8-24: WARNING: intel_scu_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/iop_wdt.c:104:8-24: WARNING: iop_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/it8712f_wdt.c:330:8-24: WARNING: it8712f_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ixp4xx_wdt.c:68:8-24: WARNING: ixp4xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ks8695_wdt.c:145:8-24: WARNING: ks8695wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/m54xx_wdt.c:88:8-24: WARNING: m54xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/machzwd.c:336:8-24: WARNING: zf_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mixcomwd.c:153:8-24: WARNING: mixcomwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mtx-1_wdt.c:121:8-24: WARNING: mtx1_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mv64x60_wdt.c:136:8-24: WARNING: mv64x60_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nuc900_wdt.c:134:8-24: WARNING: nuc900wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nv_tco.c:164:8-24: WARNING: nv_tco_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pc87413_wdt.c:289:8-24: WARNING: pc87413_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:698:8-24: WARNING: pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:737:8-24: WARNING: pcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:581:8-24: WARNING: pcipcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:623:8-24: WARNING: pcipcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:488:8-24: WARNING: usb_pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:527:8-24: WARNING: usb_pcwd_temperature_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pika_wdt.c:121:8-24: WARNING: pikawdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pnx833x_wdt.c:119:8-24: WARNING: pnx833x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rc32434_wdt.c:153:8-24: WARNING: rc32434_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rdc321x_wdt.c:145:8-24: WARNING: rdc321x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/riowd.c:79:1-17: WARNING: riowd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sa1100_wdt.c:62:8-24: WARNING: sa1100dog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc60xxwdt.c:211:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc7240_wdt.c:139:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc8360.c:274:8-24: WARNING: sbc8360_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_epx_c3.c:81:8-24: WARNING: epx_c3_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_fitpc2_wdt.c:78:8-24: WARNING: fitpc2_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sb_wdog.c:108:1-17: WARNING: sbwdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc1200wdt.c:181:8-24: WARNING: sc1200wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc520_wdt.c:261:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sch311x_wdt.c:319:8-24: WARNING: sch311x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/scx200_wdt.c:105:8-24: WARNING: scx200_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/smsc37b787_wdt.c:369:8-24: WARNING: wb_smsc_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83877f_wdt.c:227:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83977f_wdt.c:301:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wafer5823wdt.c:200:8-24: WARNING: wafwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/watchdog_dev.c:828:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:379:8-24: WARNING: wdrtas_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:445:8-24: WARNING: wdrtas_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt285.c:104:1-17: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt977.c:276:8-24: WARNING: wdt977_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:424:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:484:8-24: WARNING: wdt_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:464:8-24: WARNING: wdtpci_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:527:8-24: WARNING: wdtpci_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. net/batman-adv/log.c:105:1-17: WARNING: batadv_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/control.c:57:7-23: WARNING: snd_ctl_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/rawmidi.c:385:7-23: WARNING: snd_rawmidi_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/seq/seq_clientmgr.c:310:7-23: WARNING: snd_seq_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/timer.c:1428:7-23: WARNING: snd_timer_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. One can also recheck/review the patch via generating it with explanation comments included via $ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/stream_open.cocci SPFLAGS="-D explain" (*) This second group also contains cases with read/write deadlocks that stream_open.cocci don't yet detect, but which are still valid to convert to stream_open since ppos is not used. For example drivers/pci/switch/switchtec.c calls wait_for_completion_interruptible() in its .read, but stream_open.cocci currently detects only "wait_event*" as blocking. Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Cc: Anatolij Gustschin <agust@denx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James R. Van Zandt" <jrv@vanzandt.mv.com> Cc: Corey Minyard <minyard@acm.org> Cc: Harald Welte <laforge@gnumonks.org> Acked-by: Lubomir Rintel <lkundrak@v3.sk> [scr24x_cs] Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Johan Hovold <johan@kernel.org> Cc: David Herrmann <dh.herrmann@googlemail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: Jean Delvare <jdelvare@suse.com> Acked-by: Guenter Roeck <linux@roeck-us.net> [watchdog/* hwmon/*] Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com> Acked-by: Logan Gunthorpe <logang@deltatee.com> [drivers/pci/switch/switchtec] Acked-by: Bjorn Helgaas <bhelgaas@google.com> [drivers/pci/switch/switchtec] Cc: Benson Leung <bleung@chromium.org> Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> [platform/chrome] Cc: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [rtc/*] Cc: Mark Brown <broonie@kernel.org> Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Zwane Mwaikambo <zwanem@gmail.com> Cc: Marek Lindner <mareklindner@neomailbox.ch> Cc: Simon Wunderlich <sw@simonwunderlich.de> Cc: Antonio Quartulli <a@unstable.cc> Cc: "David S. Miller" <davem@davemloft.net> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
2019-03-26 23:51:19 +03:00
ALSA: timer: Fix zero-division by continue of uninitialized instance When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-07 15:45:31 +02:00