cbcvebase.
CVE-2023-52982
published 2025-03-27

CVE-2023-52982: In the Linux kernel, the following vulnerability has been resolved: fscache: Use wait_on_bit() to wait for the freeing of relinquished volume The freeing of…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.21%
11.9th percentile
In the Linux kernel, the following vulnerability has been resolved: fscache: Use wait_on_bit() to wait for the freeing of relinquished volume The freeing of relinquished volume will wake up the pending volume acquisition by using wake_up_bit(), however it is mismatched with wait_var_event() used in fscache_wait_on_volume_collision() and it will never wake up the waiter in the wait-queue because these two functions operate on different wait-queues. According to the implementation in fscache_wait_on_volume_collision(), if the wake-up of pending acquisition is delayed longer than 20 seconds (e.g., due to the delay of on-demand fd closing), the first wait_var_event_timeout() will timeout and the following wait_var_event() will hang forever as shown below: FS-Cache: Potential volume collision new=00000024 old=00000022 ...... INFO: task mount:1148 blocked for more than 122 seconds. Not tainted 6.1.0-rc6+ #1 task:mount state:D stack:0 pid:1148 ppid:1 Call Trace: __schedule+0x2f6/0xb80 schedule+0x67/0xe0 fscache_wait_on_volume_collision.cold+0x80/0x82 __fscache_acquire_volume+0x40d/0x4e0 erofs_fscache_register_volume+0x51/0xe0 [erofs] erofs_fscache_register_fs+0x19c/0x240 [erofs] erofs_fc_fill_super+0x746/0xaf0 [erofs] vfs_get_super+0x7d/0x100 get_tree_nodev+0x16/0x20 erofs_fc_get_tree+0x20/0x30 [erofs] vfs_get_tree+0x24/0xb0 path_mount+0x2fa/0xa90 do_mount+0x7c/0xa0 __x64_sys_mount+0x8b/0xe0 do_syscall_64+0x30/0x60 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Considering that wake_up_bit() is more selective, so fix it by using wait_on_bit() instead of wait_var_event() to wait for the freeing of relinquished volume. In addition because waitqueue_active() is used in wake_up_bit() and clear_bit() doesn't imply any memory barrier, use clear_and_wake_up_bit() to add the missing memory barrier between cursor->flags and waitqueue_active().

Affected

9 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.11-1 (bookworm)linux 6.1.11-1 (bookworm)
linuxlinux
linuxlinux>= 62ab63352350e881ae693a8236b35d7d0516c78b < 3be069f42a7b79d3149194f21cdf24bf23864cac3be069f42a7b79d3149194f21cdf24bf23864cac
linuxlinux>= 62ab63352350e881ae693a8236b35d7d0516c78b < 8226e37d82f43657da34dd770e2b38f20242ada78226e37d82f43657da34dd770e2b38f20242ada7
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.1.11-16.1.11-1
linuxlinux_kernel>= 0 < 6.1.11-16.1.11-1
linuxlinux_kernel>= 0 < 6.1.11-16.1.11-1
linuxlinux_kernel>= 5.17 < 6.1.116.1.11

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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