https://github.com/torvalds/linux
Revision 2a418cf3f5f1caf911af288e978d61c9844b0695 authored by Andy Lutomirski on 23 February 2019, 01:17:04 UTC, committed by Borislav Petkov on 25 February 2019, 19:17:05 UTC
When calling __put_user(foo(), ptr), the __put_user() macro would call
foo() in between __uaccess_begin() and __uaccess_end(). If that code
were buggy, then those bugs would be run without SMAP protection.
Fortunately, there seem to be few instances of the problem in the
kernel. Nevertheless, __put_user() should be fixed to avoid doing this.
Therefore, evaluate __put_user()'s argument before setting AC.
This issue was noticed when an objtool hack by Peter Zijlstra complained
about genregs_get() and I compared the assembly output to the C source.
[ bp: Massage commit message and fixed up whitespace. ]
Fixes: 11f1a4b9755f ("x86: reorganize SMAP handling in user space accesses")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190225125231.845656645@infradead.org
1 parent f331e76
Tip revision: 2a418cf3f5f1caf911af288e978d61c9844b0695 authored by Andy Lutomirski on 23 February 2019, 01:17:04 UTC
x86/uaccess: Don't leak the AC flag into __put_user() value evaluation
x86/uaccess: Don't leak the AC flag into __put_user() value evaluation
Tip revision: 2a418cf
| File | Mode | Size |
|---|---|---|
| governors | ||
| Kconfig | -rw-r--r-- | 1.0 KB |
| Kconfig.arm | -rw-r--r-- | 2.4 KB |
| Kconfig.mips | -rw-r--r-- | 618 bytes |
| Kconfig.powerpc | -rw-r--r-- | 480 bytes |
| Makefile | -rw-r--r-- | 1.3 KB |
| coupled.c | -rw-r--r-- | 25.6 KB |
| cpuidle-arm.c | -rw-r--r-- | 3.9 KB |
| cpuidle-at91.c | -rw-r--r-- | 1.6 KB |
| cpuidle-big_little.c | -rw-r--r-- | 6.7 KB |
| cpuidle-calxeda.c | -rw-r--r-- | 2.2 KB |
| cpuidle-clps711x.c | -rw-r--r-- | 1.5 KB |
| cpuidle-cps.c | -rw-r--r-- | 4.4 KB |
| cpuidle-exynos.c | -rw-r--r-- | 3.4 KB |
| cpuidle-kirkwood.c | -rw-r--r-- | 2.3 KB |
| cpuidle-mvebu-v7.c | -rw-r--r-- | 3.3 KB |
| cpuidle-powernv.c | -rw-r--r-- | 10.6 KB |
| cpuidle-pseries.c | -rw-r--r-- | 6.7 KB |
| cpuidle-ux500.c | -rw-r--r-- | 3.2 KB |
| cpuidle-zynq.c | -rw-r--r-- | 2.0 KB |
| cpuidle.c | -rw-r--r-- | 17.0 KB |
| cpuidle.h | -rw-r--r-- | 2.1 KB |
| driver.c | -rw-r--r-- | 8.7 KB |
| dt_idle_states.c | -rw-r--r-- | 6.5 KB |
| dt_idle_states.h | -rw-r--r-- | 216 bytes |
| governor.c | -rw-r--r-- | 2.6 KB |
| poll_state.c | -rw-r--r-- | 1.4 KB |
| sysfs.c | -rw-r--r-- | 18.3 KB |
Computing file changes ...
