cbcvebase.
CVE-2021-47281
published 2024-05-21

CVE-2021-47281: In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix race of snd_seq_timer_open() The timer instance per queue is exclusive, and…

PriorityP428high7CVSS 3.1
AVLACHPRLUINSUCHIHAH
EPSS
0.23%
14.5th percentile
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix race of snd_seq_timer_open() The timer instance per queue is exclusive, and snd_seq_timer_open() should have managed the concurrent accesses. It looks as if it's checking the already existing timer instance at the beginning, but it's not right, because there is no protection, hence any later concurrent call of snd_seq_timer_open() may override the timer instance easily. This may result in UAF, as the leftover timer instance can keep running while the queue itself gets closed, as spotted by syzkaller recently. For avoiding the race, add a proper check at the assignment of tmr->timeri again, and return -EBUSY if it's been already registered.

Affected

16 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 5.10.46-1 (bookworm)linux 5.10.46-1 (bookworm)
linuxlinux
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < bd7d88b0874f82f7b29d1a53e574cedaf23166babd7d88b0874f82f7b29d1a53e574cedaf23166ba
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 536a7646c00a0f14fee49e5e313109e5da2f6031536a7646c00a0f14fee49e5e313109e5da2f6031
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 83e197a8414c0ba545e7e3916ce05f836f34927383e197a8414c0ba545e7e3916ce05f836f349273
linuxlinux_kernel< 5.10.445.10.44
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.46-15.10.46-1
linuxlinux_kernel>= 0 < 5.10.46-15.10.46-1
linuxlinux_kernel>= 0 < 5.10.46-15.10.46-1
linuxlinux_kernel>= 0 < 5.10.46-15.10.46-1
linuxlinux_kernel>= 5.11 < 5.12.115.12.11

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_debian7.0HIGH
vendor_redhat7.0HIGH
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