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| author |   Jiashuo Liang <liangjs@pku.edu.cn> | 2021-07-30 11:01:52 +0800 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2021-09-20 22:28:47 +0200 |
| commit | d4ffd5df9d18031b6a53f934388726775b4452d3 (patch) | |
| tree | 8dc52665b1a5b1bba9e37d1baa773e7a30d7cd2c /include | |
| parent | Linux 5.15-rc2 (diff) | |
| download | linux-dev-d4ffd5df9d18031b6a53f934388726775b4452d3.tar.xz linux-dev-d4ffd5df9d18031b6a53f934388726775b4452d3.zip | |
x86/fault: Fix wrong signal when vsyscall fails with pkey
The function __bad_area_nosemaphore() calls kernelmode_fixup_or_oops()
with the parameter @signal being actually @pkey, which will send a
signal numbered with the argument in @pkey.
This bug can be triggered when the kernel fails to access user-given
memory pages that are protected by a pkey, so it can go down the
do_user_addr_fault() path and pass the !user_mode() check in
__bad_area_nosemaphore().
Most cases will simply run the kernel fixup code to make an -EFAULT. But
when another condition current->thread.sig_on_uaccess_err is met, which
is only used to emulate vsyscall, the kernel will generate the wrong
signal.
Add a new parameter @pkey to kernelmode_fixup_or_oops() to fix this.
[ bp: Massage commit message, fix build error as reported by the 0day
bot: https://lkml.kernel.org/r/202109202245.APvuT8BX-lkp@intel.com ]
Fixes: 5042d40a264c ("x86/fault: Bypass no_context() for implicit kernel faults from usermode")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jiashuo Liang <liangjs@pku.edu.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20210730030152.249106-1-liangjs@pku.edu.cn
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pkeys.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h index 6beb26b7151d..86be8bf27b41 100644 --- a/include/linux/pkeys.h +++ b/include/linux/pkeys.h @@ -4,6 +4,8 @@ #include <linux/mm.h> +#define ARCH_DEFAULT_PKEY 0 + #ifdef CONFIG_ARCH_HAS_PKEYS #include <asm/pkeys.h> #else /* ! CONFIG_ARCH_HAS_PKEYS */ |