linux/arch/x86/entry
Mathias Krause ec980b6f7d x86/vdso: Ensure vdso32_enabled gets set to valid values only
commit c06989da39 upstream.

vdso_enabled can be set to arbitrary integer values via the kernel command
line 'vdso32=' parameter or via 'sysctl abi.vsyscall32'.

load_vdso32() only maps VDSO if vdso_enabled == 1, but ARCH_DLINFO_IA32
merily checks for vdso_enabled != 0. As a consequence the AT_SYSINFO_EHDR
auxiliary vector for the VDSO_ENTRY is emitted with a NULL pointer which
causes a segfault when the application tries to use the VDSO.

Restrict the valid arguments on the command line and the sysctl to 0 and 1.

Fixes: b0b49f2673 ("x86, vdso: Remove compat vdso support")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@redhat.com>
Link: http://lkml.kernel.org/r/1491424561-7187-1-git-send-email-minipli@googlemail.com
Link: http://lkml.kernel.org/r/20170410151723.518412863@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2017-04-21 09:31:20 +02:00
..
syscalls x86, pkeys: remove cruft from never-merged syscalls 2016-10-17 14:16:13 -07:00
vdso x86/vdso: Ensure vdso32_enabled gets set to valid values only 2017-04-21 09:31:20 +02:00
vsyscall Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-07-29 17:38:46 -07:00
calling.h x86/asm/entry: Remove unused SAVE_ALL/RESTORE_ALL macros for !CONFIG_x86_64 2016-01-19 08:24:03 +01:00
common.c x86/entry: Get rid of pt_regs_to_thread_info() 2016-09-15 08:25:12 +02:00
entry_32.S ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it 2017-01-09 08:32:23 +01:00
entry_64.S Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
entry_64_compat.S x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs 2016-05-03 08:19:40 +02:00
Makefile x86/build: Fix build with older GCC versions 2016-10-25 11:44:25 +02:00
syscall_32.c x86/syscalls: Add syscall entry qualifiers 2016-01-29 09:46:38 +01:00
syscall_64.c x86/entry/64: Always run ptregs-using syscalls on the slow path 2016-01-29 09:46:38 +01:00
thunk_32.S x86: move exports to actual definitions 2016-08-07 23:47:15 -04:00
thunk_64.S x86: move exports to actual definitions 2016-08-07 23:47:15 -04:00