058f58e235
syzkaller reported a crash in ata_bmdma_fill_sg() when writing to /dev/sg1. The immediate cause was that the ATA command's scatterlist was not DMA-mapped, which causes 'pi - 1' to underflow, resulting in a write to 'qc->ap->bmdma_prd[0xffffffff]'. Strangely though, the flag ATA_QCFLAG_DMAMAP was set in qc->flags. The root cause is that when __ata_scsi_queuecmd() is preparing to relay a SCSI command to an ATAPI device, it doesn't correctly validate the CDB length before copying it into the 16-byte buffer 'cdb' in 'struct ata_queued_cmd'. Namely, it validates the fixed CDB length expected based on the SCSI opcode but not the actual CDB length, which can be larger due to the use of the SG_NEXT_CMD_LEN ioctl. Since 'flags' is the next member in ata_queued_cmd, a buffer overflow corrupts it. Fix it by requiring that the actual CDB length be <= 16 (ATAPI_CDB_LEN). [Really it seems the length should be required to be <= dev->cdb_len, but the current behavior seems to have been intentionally introduced by commit |
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| LICENSES | ||
| arch | ||
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| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
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| security | ||
| sound | ||
| tools | ||
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| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
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| README | ||
README
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.