Bug 2396494 (CVE-2022-50403) - CVE-2022-50403 kernel: ext4: fix undefined behavior in bit shift for ext4_check_flag_values
Summary: CVE-2022-50403 kernel: ext4: fix undefined behavior in bit shift for ext4_che...
Keywords:
Status: NEW
Alias: CVE-2022-50403
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-09-18 17:01 UTC by OSIDB Bzimport
Modified: 2025-09-25 22:36 UTC (History)
0 users

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Description OSIDB Bzimport 2025-09-18 17:01:26 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ext4: fix undefined behavior in bit shift for ext4_check_flag_values

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in fs/ext4/ext4.h:591:2
left shift of 1 by 31 places cannot be represented in type 'int'
Call Trace:
 <TASK>
 dump_stack_lvl+0x7d/0xa5
 dump_stack+0x15/0x1b
 ubsan_epilogue+0xe/0x4e
 __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
 ext4_init_fs+0x5a/0x277
 do_one_initcall+0x76/0x430
 kernel_init_freeable+0x3b3/0x422
 kernel_init+0x24/0x1e0
 ret_from_fork+0x1f/0x30
 </TASK>
Comment 1 Keith Grant 2025-09-18 18:56:44 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025091852-CVE-2022-50403-0471@gregkh/T
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