CVE-2024-49933

blk_iocost: fix more out of bound shifts

Published Oct 21, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

blk_iocost: fix more out of bound shifts

Recently running UBSAN caught few out of bound shifts in the
ioc_forgive_debts() function:

UBSAN: shift-out-of-bounds in block/blk-iocost.c:2142:38
shift exponent 80 is too large for 64-bit type 'u64' (aka 'unsigned long
long')
...
UBSAN: shift-out-of-bounds in block/blk-iocost.c:2144:30
shift exponent 80 is too large for 64-bit type 'u64' (aka 'unsigned long
long')
...
Call Trace:
<IRQ>
dump_stack_lvl+0xca/0x130
__ubsan_handle_shift_out_of_bounds+0x22c/0x280
? __lock_acquire+0x6441/0x7c10
ioc_timer_fn+0x6cec/0x7750
? blk_iocost_init+0x720/0x720
? call_timer_fn+0x5d/0x470
call_timer_fn+0xfa/0x470
? blk_iocost_init+0x720/0x720
__run_timer_base+0x519/0x700
...

Actual impact of this issue was not identified but I propose to fix the
undefined behaviour.
The proposed fix to prevent those out of bound shifts consist of
precalculating exponent before using it the shift operations by taking
min value from the actual exponent and maximum possible number of bits.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4008-1 linux-6.1 security update
Debian DLA Debian DLA DLA-4075-1 linux security update
Ubuntu USN Ubuntu USN USN-7166-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7166-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7166-3 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7166-4 Linux kernel (Xilinx ZynqMP) vulnerabilities
Ubuntu USN Ubuntu USN USN-7186-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-7186-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7194-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7276-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7277-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7301-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7303-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7303-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7303-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7304-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7310-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7311-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7384-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7384-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7385-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7386-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7403-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7468-1 Linux kernel (Azure, N-Series) vulnerabilities
History
Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
Weaknesses CWE-682
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: blk_iocost: fix more out of bound shifts Recently running UBSAN caught few out of bound shifts in the ioc_forgive_debts() function: UBSAN: shift-out-of-bounds in block/blk-iocost.c:2142:38 shift exponent 80 is too large for 64-bit type 'u64' (aka 'unsigned long long') ... UBSAN: shift-out-of-bounds in block/blk-iocost.c:2144:30 shift exponent 80 is too large for 64-bit type 'u64' (aka 'unsigned long long') ... Call Trace: <IRQ> dump_stack_lvl+0xca/0x130 __ubsan_handle_shift_out_of_bounds+0x22c/0x280 ? __lock_acquire+0x6441/0x7c10 ioc_timer_fn+0x6cec/0x7750 ? blk_iocost_init+0x720/0x720 ? call_timer_fn+0x5d/0x470 call_timer_fn+0xfa/0x470 ? blk_iocost_init+0x720/0x720 __run_timer_base+0x519/0x700 ... Actual impact of this issue was not identified but I propose to fix the undefined behaviour. The proposed fix to prevent those out of bound shifts consist of precalculating exponent before using it the shift operations by taking min value from the actual exponent and maximum possible number of bits.
Title blk_iocost: fix more out of bound shifts
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 11, 2026, 8:42 PM
Reserved
Oct 21, 2024, 12:17 PM
Status
Modified
Published
Oct 21, 2024, 6:15 PM
Modified
Jun 17, 2026, 8:00 AM
Severity
Moderate
Public date
Oct 21, 2024, 12:00 AM