cbcvebase.
CVE-2024-47794
published 2025-01-11

CVE-2024-47794: In the Linux kernel, the following vulnerability has been resolved: bpf: Prevent tailcall infinite loop caused by freplace There is a potential infinite loop…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.20%
9.8th percentile
In the Linux kernel, the following vulnerability has been resolved: bpf: Prevent tailcall infinite loop caused by freplace There is a potential infinite loop issue that can occur when using a combination of tail calls and freplace. In an upcoming selftest, the attach target for entry_freplace of tailcall_freplace.c is subprog_tc of tc_bpf2bpf.c, while the tail call in entry_freplace leads to entry_tc. This results in an infinite loop: entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc. The problem arises because the tail_call_cnt in entry_freplace resets to zero each time entry_freplace is executed, causing the tail call mechanism to never terminate, eventually leading to a kernel panic. To fix this issue, the solution is twofold: 1. Prevent updating a program extended by an freplace program to a prog_array map. 2. Prevent extending a program that is already part of a prog_array map with an freplace program. This ensures that: * If a program or its subprogram has been extended by an freplace program, it can no longer be updated to a prog_array map. * If a program has been added to a prog_array map, neither it nor its subprograms can be extended by an freplace program. Moreover, an extension program should not be tailcalled. As such, return -EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a prog_array map. Additionally, fix a minor code style issue by replacing eight spaces with a tab for proper formatting.

Affected

8 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.12.5-1 (forky)linux 6.12.5-1 (forky)
linuxlinux
linuxlinux>= be8704ff07d2374bcc5c675526f95e70c6459683 < 987aa730bad3e1ef66d9f30182294daa78f6387d987aa730bad3e1ef66d9f30182294daa78f6387d
linuxlinux>= be8704ff07d2374bcc5c675526f95e70c6459683 < d6083f040d5d8f8d748462c77e90547097df936ed6083f040d5d8f8d748462c77e90547097df936e
linuxlinux_kernel>= 0 < 6.12.5-16.12.5-1
linuxlinux_kernel>= 0 < 6.12.5-16.12.5-1
linuxlinux_kernel>= 0 < 6.8.0-58.606.8.0-58.60
linuxlinux_kernel>= 5.6 < 6.12.56.12.5

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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