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CVE-2024-50106
published 2024-11-05

CVE-2024-50106: In the Linux kernel, the following vulnerability has been resolved: nfsd: fix race between laundromat and free_stateid There is a race between laundromat…

PriorityP431high7CVSS 3.1
AVLACHPRLUINSUCHIHAH
EPSS
0.21%
11.5th percentile
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix race between laundromat and free_stateid There is a race between laundromat handling of revoked delegations and a client sending free_stateid operation. Laundromat thread finds that delegation has expired and needs to be revoked so it marks the delegation stid revoked and it puts it on a reaper list but then it unlock the state lock and the actual delegation revocation happens without the lock. Once the stid is marked revoked a racing free_stateid processing thread does the following (1) it calls list_del_init() which removes it from the reaper list and (2) frees the delegation stid structure. The laundromat thread ends up not calling the revoke_delegation() function for this particular delegation but that means it will no release the lock lease that exists on the file. Now, a new open for this file comes in and ends up finding that lease list isn't empty and calls nfsd_breaker_owns_lease() which ends up trying to derefence a freed delegation stateid. Leading to the followint use-after-free KASAN warning: kernel: ================================================================== kernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd] kernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205 kernel: kernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9 kernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024 kernel: Call trace: kernel: dump_backtrace+0x98/0x120 kernel: show_stack+0x1c/0x30 kernel: dump_stack_lvl+0x80/0xe8 kernel: print_address_description.constprop.0+0x84/0x390 kernel: print_report+0xa4/0x268 kernel: kasan_report+0xb4/0xf8 kernel: __asan_report_load8_noabort+0x1c/0x28 kernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd] kernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd] kernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd] kernel: nfs4_get_vfs_file+0x634/0x958 [nfsd

Affected

9 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.11.6-1 (forky)linux 6.11.6-1 (forky)
linuxlinux
linuxlinux>= 83e733161fde43e2f99cefa68e369944460fce39 < 967faa26f313a62e7bebc55d5b8122eaee43b929967faa26f313a62e7bebc55d5b8122eaee43b929
linuxlinux>= 83e733161fde43e2f99cefa68e369944460fce39 < 8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.11.6-16.11.6-1
linuxlinux_kernel>= 0 < 6.11.6-16.11.6-1
linuxlinux_kernel>= 0 < 6.11.0-18.186.11.0-18.18
linuxlinux_kernel>= 3.17 < 6.11.66.11.6

CVSS provenance

nvdv3.17.0HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.0HIGH
vendor_debian7.0LOW
vendor_redhat7.0HIGH
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