diff options
| author | Andrey Konovalov <andreyknvl@google.com> | 2021-01-15 18:41:53 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2021-01-18 18:15:49 +0000 |
| commit | 3ed86b9a7140bb9b5ff0669778e56bf9b0e582a5 (patch) | |
| tree | 52544ae5eeb8a9e27a593c5cc41ff3ebe5cb5a36 /arch/arm64/mm/fault.c | |
| parent | 3a57a643a851dbb1c4a1819394ca009e3bfa4813 (diff) | |
kasan, arm64: fix pointer tags in KASAN reports
As of the "arm64: expose FAR_EL1 tag bits in siginfo" patch, the address
that is passed to report_tag_fault has pointer tags in the format of 0x0X,
while KASAN uses 0xFX format (note the difference in the top 4 bits).
Fix up the pointer tag for kernel pointers in do_tag_check_fault by
setting them to the same value as bit 55. Explicitly use __untagged_addr()
instead of untagged_addr(), as the latter doesn't affect TTBR1 addresses.
Fixes: dceec3ff7807 ("arm64: expose FAR_EL1 tag bits in siginfo")
Fixes: 4291e9ee6189 ("kasan, arm64: print report from tag fault handler")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://linux-review.googlesource.com/id/I9ced973866036d8679e8f4ae325de547eb969649
Link: https://lore.kernel.org/r/ff30b0afe6005fd046f9ac72bfb71822aedccd89.1610731872.git.andreyknvl@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 3c40da479899..35d75c60e2b8 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -709,10 +709,11 @@ static int do_tag_check_fault(unsigned long far, unsigned int esr, struct pt_regs *regs) { /* - * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN for tag - * check faults. Mask them out now so that userspace doesn't see them. + * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN + * for tag check faults. Set them to corresponding bits in the untagged + * address. */ - far &= (1UL << 60) - 1; + far = (__untagged_addr(far) & ~MTE_TAG_MASK) | (far & MTE_TAG_MASK); do_bad_area(far, esr, regs); return 0; } |