CVE-2026-98821 PUBLISHED

block: reject polled dio with user integrity metadata

Assigner: Linux
Reserved: 25.09.2026 Published: 18.10.2026 Updated: 18.10.2026

In the Linux kernel, the following vulnerability has been resolved:

block: reject polled dio with user integrity metadata

IOCB_HAS_METADATA leaves iocb->private as a uio_meta, while iocb_bio_iopoll() expects a bio. Since 2729a60bbfb9, metadata I/O always uses __blkdev_direct_IO(), which never publishes the bio for polling, so IOPOLL calls bio_poll() on the uio_meta.

Reproducer: io_uring IOPOLL plus a PI attribute on an integrity device (scsi_debug dif=1 dix=1). KASAN reports:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004 KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] RIP: 0010:bio_poll+0x9d/0x4b0 Call Trace: iocb_bio_iopoll+0x5b/0x80 io_uring_classic_poll+0xf3/0x140 io_do_iopoll+0x4e3/0xc00 io_iopoll_check+0x275/0x560 __do_sys_io_uring_enter+0x2e5/0x720

Return -EOPNOTSUPP when HIPRI is combined with user metadata.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 2729a60bbfb9215997f25372ebe9b7964f038296 to c97ef13ad96be0e08af38dfa2ed40cded0b53e1b (excl.)
  • affected from 2729a60bbfb9215997f25372ebe9b7964f038296 to dd33c03cefccdfcb223e9e6262643d64f8c1ae20 (excl.)
  • affected from 2729a60bbfb9215997f25372ebe9b7964f038296 to 2a42e6fe1293f2e2d579c9fe5bbab056dd8b880e (excl.)
  • Version 17ecefc9fdd8c554e0d03e5a990daef19f930add is affected
  • affected from 6.16.8 to 6.17 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.17 is affected
  • unaffected from 0 to 6.17 (excl.)
  • unaffected from 6.18.56 to 6.18.* (incl.)
  • unaffected from 7.2.10 to 7.2.* (incl.)
  • unaffected from 7.3-rc6 to * (incl.)

References