CVE-2026-98821 is a vulnerability in Linux Kernel
Published on October 18, 2026
block: reject polled dio with user integrity metadata
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.
Products Associated with CVE-2026-98821
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Affected Versions
Linux:- Version 2729a60bbfb9215997f25372ebe9b7964f038296 and below c97ef13ad96be0e08af38dfa2ed40cded0b53e1b is affected.
- Version 2729a60bbfb9215997f25372ebe9b7964f038296 and below dd33c03cefccdfcb223e9e6262643d64f8c1ae20 is affected.
- Version 2729a60bbfb9215997f25372ebe9b7964f038296 and below 2a42e6fe1293f2e2d579c9fe5bbab056dd8b880e is affected.
- Version 17ecefc9fdd8c554e0d03e5a990daef19f930add is affected.
- Version 6.16.8 and below 6.17 is affected.
- Version 6.17 is affected.
- Before 6.17 is unaffected.
- Version 6.18.56, <= 6.18.* is unaffected.
- Version 7.2.10, <= 7.2.* is unaffected.
- Version 7.3-rc6, <= * is unaffected.