fsnotify: clear PARENT_WATCHED flags lazily
Published Oct 9, 2024
4.7
MEDIUMCVSS 3.1
EPSS 0.16%
Description
In some setups directories can have many (usually negative) dentries. Hence __fsnotify_update_child_dentry_flags() function can take a significant amount of time. Since the bulk of this function happens under inode->i_lock this causes a significant contention on the lock when we remove the watch from the directory as the __fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask() races with __fsnotify_update_child_dentry_flags() calls from __fsnotify_parent() happening on children. This can lead upto softlockup reports reported by users.
Fix the problem by calling fsnotify_update_children_dentry_flags() to set PARENT_WATCHED flags only when parent starts watching children.
When parent stops watching children, clear false positive PARENT_WATCHED flags lazily in __fsnotify_parent() for each accessed child.
Affected products
-
Affected
- ≥ , <
- ≥ , <
- ≥ , <
- ≥ , <
- ≥ , <
- ≥ , <
-
Affected
- 2.6.38
Unaffected
- ≥ 0, < 2.6.38
- ≥ 5.10.226, ≤ 5.10.*
- ≥ 5.15.167, ≤ 5.15.*
- ≥ 6.1.109, ≤ 6.1.*
- ≥ 6.10.9, ≤ 6.10.*
- 6.11
- ≥ 6.6.50, ≤ 6.6.*
Default status is the baseline for the product. Each version can override it (patched versions can be marked unaffected).
- < 5.10.226
- ≥ 5.11 · < 5.15.167
- ≥ 5.16 · < 6.1.109
- ≥ 6.2 · < 6.6.50
- ≥ 6.7 · < 6.10.9
No data.
Red Hat Enterprise Linux 9
kernel-0:5.14.0-570.12.1.el9_6
Fixed · RHSA-2025:6966
Red Hat Enterprise Linux 9
kernel-0:5.14.0-570.12.1.el9_6
Fixed · RHSA-2025:6966
Red Hat Enterprise Linux 6
kernel
Out of support scope
Red Hat Enterprise Linux 7
kernel
Out of support scope
Red Hat Enterprise Linux 7
kernel-rt
Out of support scope
Red Hat Enterprise Linux 8
kernel
Will not fix
Red Hat Enterprise Linux 8
kernel-rt
Will not fix
Red Hat Enterprise Linux 9
kernel-rt
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 9 | kernel-0:5.14.0-570.12.1.el9_6 | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux 9 | kernel-0:5.14.0-570.12.1.el9_6 | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | kernel | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Out of support scope | n/a |
| Red Hat Enterprise Linux 8 | kernel | Will not fix | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Will not fix | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
References (15)
- https://access.redhat.com/security/cve/CVE-2024-47660 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2317584 Issue Tracking
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://cert-portal.siemens.com/productcert/html/ssa-355557.html
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2024-42583 Advisory
- https://git.kernel.org/stable/c/172e422ffea20a89bfdc672741c1aad6fbb5044e Patch
- https://git.kernel.org/stable/c/3f3ef1d9f66b93913ce2171120d9226b55acd41d Patch
- https://git.kernel.org/stable/c/7ef1d2e240c32b1f337a37232d037b07e3919e1a Patch
- https://git.kernel.org/stable/c/d8c42405fc3507cc43ba7e4986a773c3fc633f6e Patch
- https://git.kernel.org/stable/c/f9a48bc3dd9099935751458a5bbbea4b7c28abc8 Patch
- https://git.kernel.org/stable/c/fc1b1e135c3f72382f792e6c319fc088d5523ad5 Patch
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
- https://lore.kernel.org/linux-cve-announce/2024100959-CVE-2024-47660-2d61@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2024-47660
- https://www.cve.org/CVERecord?id=CVE-2024-47660
Change history (0)
No recorded changes yet.
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