CVE-2024-36916 blk-iocost: avoid out of bounds shift
An out-of-bounds shift in the Linux kernel's blk-iocost module can cause undefined behavior, potentially leading to system instability or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-36916?
CVE-2024-36916 is a medium-severity vulnerability in Debian Debian Linux, published on 30 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
blk-iocost: avoid out of bounds shift
UBSAN catches undefined behavior in blk-iocost, where sometimes iocg->delay is shifted right by a number that is too large, resulting in undefined behavior on some architectures.
[ 186.556576] ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in block/blk-iocost.c:1366:23 shift exponent 64 is too large for 64-bit type 'u64' (aka 'unsigned long long') CPU: 16 PID: 0 Comm: swapper/16 Tainted: G S E N 6.9.0-0_fbk700_debug_rc2_kbuilder_0_gc85af715cac0 #1 Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A23 12/08/2020 Call Trace: <IRQ> dump_stack_lvl+0x8f/0xe0 __ubsan_handle_shift_out_of_bounds+0x22c/0x280 iocg_kick_delay+0x30b/0x310 ioc_timer_fn+0x2fb/0x1f80 __run_timer_base+0x1b6/0x250 ...
Avoid that undefined behavior by simply taking the "delay = 0" branch if the shift is too large.
I am not sure what the symptoms of an undefined value delay will be, but I suspect it could be more than a little annoying to debug.
Weakness: CWE-125
Which versions are affected by CVE-2024-36916?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2024-36916?
Apply the vendor's patch.
Is CVE-2024-36916 being exploited?
There is no known exploitation of CVE-2024-36916 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2024-36916, DEBIAN-CVE-2024-36916, UBUNTU-CVE-2024-36916.