On Mon, Sep 20, 2021 at 10:42:39AM -0000, tip-bot2 for Jiashuo Liang wrote:
> The following commit has been merged into the x86/urgent branch of tip:
>
> Commit-ID: 0829d0b6bf0fb3453608798442deaf00c4a1abec
> Gitweb: https://git.kernel.org/tip/0829d0b6bf0fb3453608798442deaf00c4a1abec
> Author: Jiashuo Liang <liangjs@xxxxxxxxxx>
> AuthorDate: Fri, 30 Jul 2021 11:01:52 +08:00
> Committer: Borislav Petkov <bp@xxxxxxx>
> CommitterDate: Mon, 20 Sep 2021 12:31:06 +02:00
>
> 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. ]
>
> Fixes: 5042d40a264c ("x86/fault: Bypass no_context() for implicit kernel faults from usermode")
> Signed-off-by: Jiashuo Liang <liangjs@xxxxxxxxxx>
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Link: https://lkml.kernel.org/r/20210730030152.249106-1-liangjs@xxxxxxxxxx
> ---
> arch/x86/mm/fault.c | 26 ++++++++++++++++++--------
> 1 file changed, 18 insertions(+), 8 deletions(-)
Zapping it again because the 0day bot found some randconfig which fails:
https://lkml.kernel.org/r/202109202245.APvuT8BX-lkp@xxxxxxxxx
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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