CVE-2022-48635: fsdax: Fix infinite loop in dax_iomap_rw()

Severity: medium (CVSS 6.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-28 · updated 2026-06-17
Weakness: CWE-835

Description

In the Linux kernel, the following vulnerability has been resolved: fsdax: Fix infinite loop in dax_iomap_rw() I got an infinite loop and a WARNING report when executing a tail command in virtiofs. WARNING: CPU: 10 PID: 964 at fs/iomap/iter.c:34 iomap_iter+0x3a2/0x3d0 Modules linked in: CPU: 10 PID: 964 Comm: tail Not tainted 5.19.0-rc7 Call Trace: <TASK> dax_iomap_rw+0xea/0x620 ? __this_cpu_preempt_check+0x13/0x20 fuse_dax_read_iter+0x47/0x80 fuse_file_read_iter+0xae/0xd0 new_sync_read+0xfe/0x180 ? 0xffffffff81000000 vfs_read+0x14d/0x1a0 ksys_read+0x6d/0xf0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The tail command will call read() with a count of 0. In this case, iomap_iter() will report this WARNING, and always return 1 which casuing the infinite loop in dax_iomap_rw(). Fixing by checking count whether is 0 in dax_iomap_rw().

Affected products

Linux kernel: from 5.15 before 5.15.71; from 5.16 before 5.19.12; 6.0-rc1, 6.0-rc2, 6.0-rc3, 6.0-rc4, 6.0-rc5, 6.0-rc6 — fixed in 5.15.71, 5.19.12

How to fix

Upgrade to a fixed version: Linux kernel 5.15.71, 5.19.12. Check the vendor advisory for mitigations.

References

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