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| author | Petr Vaganov <p.vaganov@ideco.ru> | 2026-06-29 01:52:21 +0700 |
|---|---|---|
| committer | Martin K. Petersen (Oracle) <mkp@kernel.org> | 2026-08-07 13:50:42 -0400 |
| commit | 626147717bea776b61ed3631d2c26283760c4cc4 (patch) | |
| tree | 1c5c38c44be3d15e19ca54b08552c329d5e94cfd /tools/perf/scripts/python/export-to-sqlite.py | |
| parent | 3ad1010413403ff1a85a7c3527b0cfe815bdada7 (diff) | |
scsi: core: Fill in DMA padding bytes in scsi_alloc_sgtables()
During fuzz testing, the following issue was discovered:
BUG: KMSAN: uninit-value in __dma_map_sg_attrs+0x217/0x310
__dma_map_sg_attrs+0x217/0x310
dma_map_sg_attrs+0x4a/0x70
ata_qc_issue+0x9f8/0x1420
__ata_scsi_queuecmd+0x1657/0x1740
ata_scsi_queuecmd+0x79a/0x920
scsi_queue_rq+0x4472/0x4f40
blk_mq_dispatch_rq_list+0x1cca/0x3ee0
__blk_mq_sched_dispatch_requests+0x458/0x630
blk_mq_sched_dispatch_requests+0x15b/0x340
__blk_mq_run_hw_queue+0xe5/0x250
__blk_mq_delay_run_hw_queue+0x138/0x780
blk_mq_run_hw_queue+0x4bb/0x7e0
blk_mq_sched_insert_request+0x2a7/0x4c0
blk_execute_rq+0x497/0x8a0
sg_io+0xbe0/0xe20
scsi_ioctl+0x2b36/0x3c60
sr_block_ioctl+0x319/0x440
blkdev_ioctl+0x80f/0xd70
__se_sys_ioctl+0x219/0x420
__x64_sys_ioctl+0x93/0xe0
x64_sys_call+0x1d6c/0x3ad0
do_syscall_64+0x4c/0xa0
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Uninit was created at:
__alloc_pages+0x5c0/0xc80
alloc_pages+0xe0e/0x1050
blk_rq_map_user_iov+0x2b77/0x6100
blk_rq_map_user_io+0x2fa/0x4d0
sg_io+0xad6/0xe20
scsi_ioctl+0x2b36/0x3c60
sr_block_ioctl+0x319/0x440
blkdev_ioctl+0x80f/0xd70
__se_sys_ioctl+0x219/0x420
__x64_sys_ioctl+0x93/0xe0
x64_sys_call+0x1d6c/0x3ad0
do_syscall_64+0x4c/0xa0
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Bytes 14-15 of 16 are uninitialized
Memory access of size 16 starts at ffff88800cbdb000
When processing the last unaligned element of the scatterlist, it is
supplemented with missing bytes in the amount of pad_len. These bytes
remain uninitialized, which leads to a problem.
Extend last_sg->length by pad_len first, then use sg_zero_buffer() to
zero those pad_len bytes. sg_zero_buffer() uses sg_miter internally,
which correctly handles sg entries spanning multiple pages and padding
that crosses a page boundary.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 40b01b9bbdf5 ("block: update bio according to DMA alignment padding")
Cc: stable@vger.kernel.org
Signed-off-by: Petr Vaganov <p.vaganov@ideco.ru>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260628185229.37957-1-p.vaganov@ideco.ru
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>
Diffstat (limited to 'tools/perf/scripts/python/export-to-sqlite.py')
0 files changed, 0 insertions, 0 deletions