CVE-2022-49706: zonefs: fix zonefs_iomap_begin() for reads

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.

Scores

CVSS scores of CVE-2022-49706, by who scored it
Scored by	CVSS	Score	Vector
NVDNVD · Analyzed	3.1	High7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

EPSS (exploitation in 30 days): 0.27% · top 81% of all CVEs (7 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.

Weakness

CWE-125 (opens in a new tab)All about CWE-125 and its CVEs

Affected products

Linux · Linux
- affected 8dcc1a9d90c10fa4143e5c17821082e5e60e46a1 – < 355be6131164c5bacf2e810763835aecb6e01fcb
- affected 8dcc1a9d90c10fa4143e5c17821082e5e60e46a1 – < c2f71b9bb398e2e573bdc2574149f42b45efe410
- affected 8dcc1a9d90c10fa4143e5c17821082e5e60e46a1 – < 3a7f05f104347b407e865c10be2675cd833a4e48
- affected 8dcc1a9d90c10fa4143e5c17821082e5e60e46a1 – < c1c1204c0d0c1dccc1310b9277fb2bd8b663d8fe
Linux · Linux
- affected 5.6
- unaffected < 5.6
- unaffected 5.10.125 – ≤ 5.10.*
- unaffected 5.15.50 – ≤ 5.15.*
- unaffected 5.18.7 – ≤ 5.18.*
- unaffected 5.19 – ≤ *

References (4)

Sources

The same CVE in the primary databases and aggregators, to check against.

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Record last updated 11 May 2026, 19:05 UTC.