Bug 2555155 (CVE-2026-98722) - CVE-2026-98722 kernel: mtd: block2mtd: Fix divide error when erase_size is zero
Summary: CVE-2026-98722 kernel: mtd: block2mtd: Fix divide error when erase_size is zero
Keywords:
Status: NEW
Alias: CVE-2026-98722
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: 2026-10-18 15:57 UTC by OSIDB Bzimport
Modified: 2026-10-22 18:17 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2026-10-18 15:57:33 UTC
In the Linux kernel, the following vulnerability has been resolved:

mtd: block2mtd: Fix divide error when erase_size is zero

The erase size is parsed from the "block2mtd" module parameter and can
be set to zero. add_device() then evaluates

        if (size % erase_size)

with a zero divisor, which triggers a divide error:

divide error: 0000 [#1] PREEMPT SMP PTI
RIP: 0010:add_device drivers/mtd/devices/block2mtd.c:296 [inline]
RIP: 0010:block2mtd_setup2+0x592/0xda0 drivers/mtd/devices/block2mtd.c:459
Call Trace:
block2mtd_setup+0x27/0xe0 drivers/mtd/devices/block2mtd.c:476
param_attr_store+0x214/0x310 kernel/params.c:589
module_attr_store+0x65/0x90 kernel/params.c:904
kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
...

Reject a zero erase size before performing the modulo operation so the
existing "erasesize must be a divisor of device size" error path
reports the invalid argument and frees the device.


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