{"id":"DEBIAN-CVE-2021-47335","details":"In the Linux kernel, the following vulnerability has been resolved:  f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances  As syzbot reported, there is an use-after-free issue during f2fs recovery:  Use-after-free write at 0xffff88823bc16040 (in kfence-#10):  kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486  f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869  f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945  mount_bdev+0x26c/0x3a0 fs/super.c:1367  legacy_get_tree+0xea/0x180 fs/fs_context.c:592  vfs_get_tree+0x86/0x270 fs/super.c:1497  do_new_mount fs/namespace.c:2905 [inline]  path_mount+0x196f/0x2be0 fs/namespace.c:3235  do_mount fs/namespace.c:3248 [inline]  __do_sys_mount fs/namespace.c:3456 [inline]  __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433  do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47  entry_SYSCALL_64_after_hwframe+0x44/0xae  The root cause is multi f2fs filesystem instances can race on accessing global fsync_entry_slab pointer, result in use-after-free issue of slab cache, fixes to init/destroy this slab cache only once during module init/destroy procedure to avoid this issue.","modified":"2026-09-15T09:02:39.843051173Z","published":"2024-05-21T15:15:20.350Z","upstream":["CVE-2021-47335"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2021-47335"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.14.6-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47335.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.14.6-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47335.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.14.6-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47335.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}