Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: 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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 40b01b9bbdf51ae543a04744283bf2d56c4a6afa before 1aa6df61cef1f47f503c3ccf60d08c4dd931fdc1; affected 40b01b9bbdf51ae543a04744283bf2d56c4a6afa before 6da140ebdfdd6aa3773945f2c0ebba01d2ef33d8; affected 40b01b9bbdf51ae543a04744283bf2d56c4a6afa before fd2cbe08c6ccba7fc1ddb830653a93bb7e2d833c; affected 40b01b9bbdf51ae543a04744283bf2d56c4a6afa before 28ed5343666ff424ce5e248fa1c5a402303b4aff; affected 40b01b9bbdf51ae543a04744283bf2d56c4a6afa before a4353ec7742bdf87dcdde5875270feb3a1982a51; affected 40b01b9bbdf51ae543a04744283bf2d56c4a6afa before e7143c3f4e5c0a7986733c6f27009274bf6c4264; affected 40b01b9bbdf51ae543a04744283bf2d56c4a6afa before 6fd1cce5018fdcc8d928e00a6a1dd2997d5b9409; affected 40b01b9bbdf51ae543a04744283bf2d56c4a6afa before 626147717bea776b61ed3631d2c26283760c4cc4 |
| Linux / Linux | affected 2.6.25; unaffected 0 before 2.6.25; unaffected 5.10.270 through 5.10.*; unaffected 5.15.221 through 5.15.*; unaffected 6.1.188 through 6.1.*; unaffected 6.6.157 through 6.6.*; unaffected 6.12.109 through 6.12.*; unaffected 6.18.50 through 6.18.*; unaffected 7.2.4 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/1aa6df61cef1f47f503c3ccf60d08c4dd931fdc1
- https://git.kernel.org/stable/c/6da140ebdfdd6aa3773945f2c0ebba01d2ef33d8
- https://git.kernel.org/stable/c/fd2cbe08c6ccba7fc1ddb830653a93bb7e2d833c
- https://git.kernel.org/stable/c/28ed5343666ff424ce5e248fa1c5a402303b4aff
- https://git.kernel.org/stable/c/a4353ec7742bdf87dcdde5875270feb3a1982a51
- https://git.kernel.org/stable/c/e7143c3f4e5c0a7986733c6f27009274bf6c4264
- https://git.kernel.org/stable/c/6fd1cce5018fdcc8d928e00a6a1dd2997d5b9409
- https://git.kernel.org/stable/c/626147717bea776b61ed3631d2c26283760c4cc4