https://github.com/torvalds/linux
Revision d8f117abb380ba968b5e3ef2042d901c02872a4c authored by Uladzislau Rezki on 23 May 2020, 05:23:12 UTC, committed by Linus Torvalds on 23 May 2020, 17:26:32 UTC
free_handle() for a foreign handle may race with inter-page compaction,
what can lead to memory corruption.
To avoid that, take write lock not read lock in free_handle to be
synchronized with __release_z3fold_page().
For example KASAN can detect it:
==================================================================
BUG: KASAN: use-after-free in LZ4_decompress_safe+0x2c4/0x3b8
Read of size 1 at addr ffffffc976695ca3 by task GoogleApiHandle/4121
CPU: 0 PID: 4121 Comm: GoogleApiHandle Tainted: P S OE 4.19.81-perf+ #162
Hardware name: Sony Mobile Communications. PDX-203(KONA) (DT)
Call trace:
LZ4_decompress_safe+0x2c4/0x3b8
lz4_decompress_crypto+0x3c/0x70
crypto_decompress+0x58/0x70
zcomp_decompress+0xd4/0x120
...
Apart from that, initialize zhdr->mapped_count in init_z3fold_page() and
remove "newpage" variable because it is not used anywhere.
Signed-off-by: Uladzislau Rezki <uladzislau.rezki@sony.com>
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Raymond Jennings <shentino@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200520082100.28876-1-vitaly.wool@konsulko.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent c2bc26f
Tip revision: d8f117abb380ba968b5e3ef2042d901c02872a4c authored by Uladzislau Rezki on 23 May 2020, 05:23:12 UTC
z3fold: fix use-after-free when freeing handles
z3fold: fix use-after-free when freeing handles
Tip revision: d8f117a
| File | Mode | Size |
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | -rw-r--r-- | 15.8 KB |
| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 71 bytes |
| .gitattributes | -rw-r--r-- | 62 bytes |
| .gitignore | -rw-r--r-- | 1.7 KB |
| .mailmap | -rw-r--r-- | 15.2 KB |
| COPYING | -rw-r--r-- | 496 bytes |
| CREDITS | -rw-r--r-- | 97.4 KB |
| Kbuild | -rw-r--r-- | 1.3 KB |
| Kconfig | -rw-r--r-- | 595 bytes |
| MAINTAINERS | -rw-r--r-- | 539.3 KB |
| Makefile | -rw-r--r-- | 60.3 KB |
| README | -rw-r--r-- | 727 bytes |
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