cbcvebase.
CVE-2024-42063
published 2024-07-29

CVE-2024-42063: In the Linux kernel, the following vulnerability has been resolved: bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode syzbot reported…

PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.22%
12.9th percentile
In the Linux kernel, the following vulnerability has been resolved: bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode syzbot reported uninit memory usages during map_{lookup,delete}_elem. BUG: KMSAN: uninit-value in __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline] BUG: KMSAN: uninit-value in dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796 __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline] dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796 ____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline] bpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38 ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997 __bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237 The reproducer should be in the interpreter mode. The C reproducer is trying to run the following bpf prog: 0: (18) r0 = 0x0 2: (18) r1 = map[id:49] 4: (b7) r8 = 16777216 5: (7b) *(u64 *)(r10 -8) = r8 6: (bf) r2 = r10 7: (07) r2 += -229 ^^^^^^^^^^ 8: (b7) r3 = 8 9: (b7) r4 = 0 10: (85) call dev_map_lookup_elem#1543472 11: (95) exit It is due to the "void *key" (r2) passed to the helper. bpf allows uninit stack memory access for bpf prog with the right privileges. This patch uses kmsan_unpoison_memory() to mark the stack as initialized. This should address different syzbot reports on the uninit "void *key" argument during map_{lookup,delete}_elem.

Affected

14 ranges
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>= bd4cf0ed331a275e9bf5a49e6d0fd55dffc551b8 < b30f3197a6cd080052d5d4973f9a6b479fd9fff5b30f3197a6cd080052d5d4973f9a6b479fd9fff5
linuxlinux>= bd4cf0ed331a275e9bf5a49e6d0fd55dffc551b8 < d812ae6e02bd6e6a9cd1fdb09519c2f33e875fafd812ae6e02bd6e6a9cd1fdb09519c2f33e875faf
linuxlinux>= bd4cf0ed331a275e9bf5a49e6d0fd55dffc551b8 < 3189983c26108cf0990e5c46856dc9feb9470d123189983c26108cf0990e5c46856dc9feb9470d12
linuxlinux>= bd4cf0ed331a275e9bf5a49e6d0fd55dffc551b8 < e8742081db7d01f980c6161ae1e8a1dbc1e30979e8742081db7d01f980c6161ae1e8a1dbc1e30979
linuxlinux_kernel< 6.1.976.1.97
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 < 6.8.0-48.486.8.0-48.48
linuxlinux_kernel>= 6.2 < 6.6.376.6.37
linuxlinux_kernel>= 6.7 < 6.9.86.9.8

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
vendor_ubuntu5.5MEDIUM
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