diff options
author | Vincenzo Frascino <vincenzo.frascino@arm.com> | 2021-02-04 18:32:49 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-05 11:03:47 -0800 |
commit | 49c6631d3b4f61a7b5bb0453a885a12bfa06ffd8 (patch) | |
tree | 30d6ff4613d27c5eedece9fdbbb648c5f52e80b4 /include | |
parent | da74240eb3fcd806edb1643874363e954d9e948b (diff) |
kasan: add explicit preconditions to kasan_report()
Patch series "kasan: Fix metadata detection for KASAN_HW_TAGS", v5.
With the introduction of KASAN_HW_TAGS, kasan_report() currently assumes
that every location in memory has valid metadata associated. This is
due to the fact that addr_has_metadata() returns always true.
As a consequence of this, an invalid address (e.g. NULL pointer
address) passed to kasan_report() when KASAN_HW_TAGS is enabled, leads
to a kernel panic.
Example below, based on arm64:
BUG: KASAN: invalid-access in 0x0
Read at addr 0000000000000000 by task swapper/0/1
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
ESR = 0x96000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000004
CM = 0, WnR = 0
...
Call trace:
mte_get_mem_tag+0x24/0x40
kasan_report+0x1a4/0x410
alsa_sound_last_init+0x8c/0xa4
do_one_initcall+0x50/0x1b0
kernel_init_freeable+0x1d4/0x23c
kernel_init+0x14/0x118
ret_from_fork+0x10/0x34
Code: d65f03c0 9000f021 f9428021 b6cfff61 (d9600000)
---[ end trace 377c8bb45bdd3a1a ]---
hrtimer: interrupt took 48694256 ns
note: swapper/0[1] exited with preempt_count 1
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
SMP: stopping secondary CPUs
Kernel Offset: 0x35abaf140000 from 0xffff800010000000
PHYS_OFFSET: 0x40000000
CPU features: 0x0a7e0152,61c0a030
Memory Limit: none
---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---
This series fixes the behavior of addr_has_metadata() that now returns
true only when the address is valid.
This patch (of 2):
With the introduction of KASAN_HW_TAGS, kasan_report() accesses the
metadata only when addr_has_metadata() succeeds.
Add a comment to make sure that the preconditions to the function are
explicitly clarified.
Link: https://lkml.kernel.org/r/20210126134409.47894-1-vincenzo.frascino@arm.com
Link: https://lkml.kernel.org/r/20210126134409.47894-2-vincenzo.frascino@arm.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/kasan.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/kasan.h b/include/linux/kasan.h index fe1ae73ff8b5..0aea9e2a2a01 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -333,6 +333,13 @@ static inline void *kasan_reset_tag(const void *addr) return (void *)arch_kasan_reset_tag(addr); } +/** + * kasan_report - print a report about a bad memory access detected by KASAN + * @addr: address of the bad access + * @size: size of the bad access + * @is_write: whether the bad access is a write or a read + * @ip: instruction pointer for the accessibility check or the bad access itself + */ bool kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip); |