commit f8e1fc918a upstream.
syzbot reported a general protection fault in vidtv_psi_desc_assign [1].
vidtv_psi_pmt_stream_init() can return NULL on memory allocation
failure, but vidtv_channel_pmt_match_sections() does not check for
this. When tail is NULL, the subsequent call to
vidtv_psi_desc_assign(&tail->descriptor, desc) dereferences a NULL
pointer offset, causing a general protection fault.
Add a NULL check after vidtv_psi_pmt_stream_init(). On failure, clean
up the already-allocated stream chain and return.
[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:vidtv_psi_desc_assign+0x24/0x90 drivers/media/test-drivers/vidtv/vidtv_psi.c:629
Call Trace:
<TASK>
vidtv_channel_pmt_match_sections drivers/media/test-drivers/vidtv/vidtv_channel.c:349 [inline]
vidtv_channel_si_init+0x1445/0x1a50 drivers/media/test-drivers/vidtv/vidtv_channel.c:479
vidtv_mux_init+0x526/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:519
vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline]
vidtv_start_feed+0x33e/0x4d0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239
Fixes: f90cf6079b ("media: vidtv: add a bridge driver")
Cc: stable@vger.kernel.org
Reported-by: syzbot+1f5bcc7c919ec578777a@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1f5bcc7c919ec578777a
Signed-off-by: Ruslan Valiyev <linuxoid@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5c986b7720