CVE-2022-49706

zonefs: fix zonefs_iomap_begin() for reads

HIGH

7.1

CVSS Score

Published: February 26, 2025 at 02:24 AM UTC

Updated: June 17, 2026 at 05:18 AM UTC

1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

HIGH7.1

Exploit prediction

EPSS 0.3%

Description

In the Linux kernel, the following vulnerability has been resolved: zonefs: fix zonefs_iomap_begin() for reads If a readahead is issued to a sequential zone file with an offset exactly equal to the current file size, the iomap type is set to IOMAP_UNWRITTEN, which will prevent an IO, but the iomap length is calculated as 0. This causes a WARN_ON() in iomap_iter(): [17309.548939] WARNING: CPU: 3 PID: 2137 at fs/iomap/iter.c:34 iomap_iter+0x9cf/0xe80 [...] [17309.650907] RIP: 0010:iomap_iter+0x9cf/0xe80 [...] [17309.754560] Call Trace: [17309.757078] <TASK> [17309.759240] ? lock_is_held_type+0xd8/0x130 [17309.763531] iomap_readahead+0x1a8/0x870 [17309.767550] ? iomap_read_folio+0x4c0/0x4c0 [17309.771817] ? lockdep_hardirqs_on_prepare+0x400/0x400 [17309.778848] ? lock_release+0x370/0x750 [17309.784462] ? folio_add_lru+0x217/0x3f0 [17309.790220] ? reacquire_held_locks+0x4e0/0x4e0 [17309.796543] read_pages+0x17d/0xb60 [17309.801854] ? folio_add_lru+0x238/0x3f0 [17309.807573] ? readahead_expand+0x5f0/0x5f0 [17309.813554] ? policy_node+0xb5/0x140 [17309.819018] page_cache_ra_unbounded+0x27d/0x450 [17309.825439] filemap_get_pages+0x500/0x1450 [17309.831444] ? filemap_add_folio+0x140/0x140 [17309.837519] ? lock_is_held_type+0xd8/0x130 [17309.843509] filemap_read+0x28c/0x9f0 [17309.848953] ? zonefs_file_read_iter+0x1ea/0x4d0 [zonefs] [17309.856162] ? trace_contention_end+0xd6/0x130 [17309.862416] ? __mutex_lock+0x221/0x1480 [17309.868151] ? zonefs_file_read_iter+0x166/0x4d0 [zonefs] [17309.875364] ? filemap_get_pages+0x1450/0x1450 [17309.881647] ? __mutex_unlock_slowpath+0x15e/0x620 [17309.888248] ? wait_for_completion_io_timeout+0x20/0x20 [17309.895231] ? lock_is_held_type+0xd8/0x130 [17309.901115] ? lock_is_held_type+0xd8/0x130 [17309.906934] zonefs_file_read_iter+0x356/0x4d0 [zonefs] [17309.913750] new_sync_read+0x2d8/0x520 [17309.919035] ? __x64_sys_lseek+0x1d0/0x1d0 Furthermore, this causes iomap_readahead() to loop forever as iomap_readahead_iter() always returns 0, making no progress. Fix this by treating reads after the file size as access to holes, setting the iomap type to IOMAP_HOLE, the iomap addr to IOMAP_NULL_ADDR and using the length argument as is for the iomap length. To simplify the code with this change, zonefs_iomap_begin() is split into the read variant, zonefs_read_iomap_begin() and zonefs_read_iomap_ops, and the write variant, zonefs_write_iomap_begin() and zonefs_write_iomap_ops.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

5.11 ≤ v < 5.15.505.16 ≤ v < 5.18.75.6 ≤ v < 5.10.1255.6 ≤ v < 5.15.505.6 ≤ v < 5.18.75.6 ≤ v < 5.195.19 rc1 5.68dcc1a9d90c10fa4143e5c17821082e5e60e46a1

Vendor states this is fixed in 355be6131164c5bacf2e810763835aecb6e01fcb (fixed)

Vendor states this is fixed in 3a7f05f104347b407e865c10be2675cd833a4e48 (fixed)

Vendor states this is fixed in c1c1204c0d0c1dccc1310b9277fb2bd8b663d8fe (fixed)

Vendor states this is fixed in c2f71b9bb398e2e573bdc2574149f42b45efe410 (fixed)

Vendor states this is fixed in 5.10.125 (unaffected)

Vendor states this is fixed in 5.15.50 (unaffected)

Vendor states this is fixed in 5.18.7 (unaffected)

Vendor states this is fixed in 5.19 (unaffected)

Vendor states this is fixed in 5.6 (unaffected)