cbcvebase.
CVE-2024-42096
published 2024-07-29

CVE-2024-42096: In the Linux kernel, the following vulnerability has been resolved: x86: stop playing stack games in profile_pc() The 'profile_pc()' function is used for…

PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.24%
14.9th percentile
In the Linux kernel, the following vulnerability has been resolved: x86: stop playing stack games in profile_pc() The 'profile_pc()' function is used for timer-based profiling, which isn't really all that relevant any more to begin with, but it also ends up making assumptions based on the stack layout that aren't necessarily valid. Basically, the code tries to account the time spent in spinlocks to the caller rather than the spinlock, and while I support that as a concept, it's not worth the code complexity or the KASAN warnings when no serious profiling is done using timers anyway these days. And the code really does depend on stack layout that is only true in the simplest of cases. We've lost the comment at some point (I think when the 32-bit and 64-bit code was unified), but it used to say: Assume the lock function has either no stack frame or a copy of eflags from PUSHF. which explains why it just blindly loads a word or two straight off the stack pointer and then takes a minimal look at the values to just check if they might be eflags or the return pc: Eflags always has bits 22 and up cleared unlike kernel addresses but that basic stack layout assumption assumes that there isn't any lock debugging etc going on that would complicate the code and cause a stack frame. It causes KASAN unhappiness reported for years by syzkaller [1] and others [2]. With no real practical reason for this any more, just remove the code. Just for historical interest, here's some background commits relating to this code from 2006: 0cb91a229364 ("i386: Account spinlocks to the caller during profiling for !FP kernels") 31679f38d886 ("Simplify profile_pc on x86-64") and a code unification from 2009: ef4512882dbe ("x86: time_32/64.c unify profile_pc") but the basics of this thing actually goes back to before the git tree.

Affected

26 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.98-1 (bookworm)linux 6.1.98-1 (bookworm)
debianlinux-6.1< linux 6.1.98-1 (bookworm)linux 6.1.98-1 (bookworm)
linuxlinux
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 65ebdde16e7f5da99dbf8a548fb635837d78384e65ebdde16e7f5da99dbf8a548fb635837d78384e
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 27c3be840911b15a3f24ed623f86153c825b6b2927c3be840911b15a3f24ed623f86153c825b6b29
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 49c09ca35a5f521d7fa18caf62fdf378f15e8aa449c09ca35a5f521d7fa18caf62fdf378f15e8aa4
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 2d07fea561d64357fb7b3f3751e653bf20306d772d07fea561d64357fb7b3f3751e653bf20306d77
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 161cef818545ecf980f0e2ebaf8ba7326ce53c2b161cef818545ecf980f0e2ebaf8ba7326ce53c2b
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 16222beb9f8e5ceb0beeb5cbe54bef16df501a9216222beb9f8e5ceb0beeb5cbe54bef16df501a92
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a3b65c8cbc139bfce9541bc81c1bb766e5ba3f68a3b65c8cbc139bfce9541bc81c1bb766e5ba3f68
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 093d9603b60093a9aaae942db56107f6432a5dca093d9603b60093a9aaae942db56107f6432a5dca
linuxlinux_kernel< 4.19.3174.19.317
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.221-15.10.221-1
linuxlinux_kernel>= 0 < 6.1.98-16.1.98-1
linuxlinux_kernel>= 0 < 6.9.8-16.9.8-1
linuxlinux_kernel>= 0 < 6.9.8-16.9.8-1
linuxlinux_kernel>= 0 < 5.4.0-195.2155.4.0-195.215
linuxlinux_kernel>= 0 < 5.15.0-121.1315.15.0-121.131
linuxlinux_kernel>= 0 < 6.8.0-48.486.8.0-48.48
linuxlinux_kernel>= 4.20 < 5.4.2795.4.279
linuxlinux_kernel>= 5.11 < 5.15.1625.15.162
linuxlinux_kernel>= 5.16 < 6.1.976.1.97
linuxlinux_kernel>= 5.5 < 5.10.2215.10.221
linuxlinux_kernel>= 6.2 < 6.6.376.6.37

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.8HIGH
vendor_ubuntu7.8HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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