CVE-2024-46701: libfs: fix infinite directory reads for offset dir
First published: Fri Sep 13 2024(Updated: )
In the Linux kernel, the following vulnerability has been resolved: libfs: fix infinite directory reads for offset dir After we switch tmpfs dir operations from simple_dir_operations to simple_offset_dir_operations, every rename happened will fill new dentry to dest dir's maple tree(&SHMEM_I(inode)->dir_offsets->mt) with a free key starting with octx->newx_offset, and then set newx_offset equals to free key + 1. This will lead to infinite readdir combine with rename happened at the same time, which fail generic/736 in xfstests(detail show as below). 1. create 5000 files(1 2 3...) under one dir 2. call readdir(man 3 readdir) once, and get one entry 3. rename(entry, "TEMPFILE"), then rename("TEMPFILE", entry) 4. loop 2~3, until readdir return nothing or we loop too many times(tmpfs break test with the second condition) We choose the same logic what commit 9b378f6ad48cf ("btrfs: fix infinite directory reads") to fix it, record the last_index when we open dir, and do not emit the entry which index >= last_index. The file->private_data now used in offset dir can use directly to do this, and we also update the last_index when we llseek the dir file. [brauner: only update last_index after seek when offset is zero like Jan suggested]
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 416baaa9-dc9f-4396-8d5f-8c081fb06d67
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Linux kernel | >=6.6<6.10.7 | |
| Linux Linux kernel | =6.11-rc1 | |
| Linux Linux kernel | =6.11-rc2 | |
| Linux Linux kernel | =6.11-rc3 | |
| debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.119-1 6.11.10-1 6.12.5-1 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
- https://git.kernel.org/stable/c/308b4fc2403b335894592ee9dc212a5e58bb309f
- https://git.kernel.org/stable/c/64a7ce76fb901bf9f9c36cf5d681328fc0fd4b5a
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-46701
- https://nvd.nist.gov/vuln/detail/CVE-2024-46701
- https://launchpad.net/bugs/cve/CVE-2024-46701
- https://security-tracker.debian.org/tracker/CVE-2024-46701
- https://ubuntu.com/security/CVE-2024-46701
- https://git.kernel.org/linus/64a7ce76fb901bf9f9c36cf5d681328fc0fd4b5a
- agent/title
- agent/type
- agent/first-publish-date
- collector/nvd-api
- source/NVD
- agent/software-canonical-lookup
- agent/severity
- agent/remedy
- agent/weakness
- agent/references
- agent/author
- collector/nvd-cve
- agent/tags
- collector/usn-cve
- source/Ubuntu
- agent/description
- agent/event
- collector/security-tracker-debian
- source/Debian
- agent/softwarecombine
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/trending
- vendor/linux
- canonical/linux linux kernel
- version/linux linux kernel/6.6
- version/linux linux kernel/6.11-rc1
- version/linux linux kernel/6.11-rc2
- version/linux linux kernel/6.11-rc3
- package-manager/debian