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 |
|---|---|---|
| unittest-data | ||
| Kconfig | -rw-r--r-- | 2.3 KB |
| Makefile | -rw-r--r-- | 659 bytes |
| address.c | -rw-r--r-- | 24.1 KB |
| base.c | -rw-r--r-- | 58.7 KB |
| device.c | -rw-r--r-- | 8.2 KB |
| dynamic.c | -rw-r--r-- | 22.7 KB |
| fdt.c | -rw-r--r-- | 32.1 KB |
| fdt_address.c | -rw-r--r-- | 6.2 KB |
| irq.c | -rw-r--r-- | 18.6 KB |
| kobj.c | -rw-r--r-- | 3.8 KB |
| of_mdio.c | -rw-r--r-- | 13.8 KB |
| of_net.c | -rw-r--r-- | 2.4 KB |
| of_numa.c | -rw-r--r-- | 3.9 KB |
| of_private.h | -rw-r--r-- | 5.4 KB |
| of_reserved_mem.c | -rw-r--r-- | 10.3 KB |
| overlay.c | -rw-r--r-- | 34.3 KB |
| pdt.c | -rw-r--r-- | 4.9 KB |
| platform.c | -rw-r--r-- | 19.8 KB |
| property.c | -rw-r--r-- | 28.6 KB |
| resolver.c | -rw-r--r-- | 8.5 KB |
| unittest.c | -rw-r--r-- | 68.5 KB |
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