Integer Overflow or Wraparound Affecting kernel-zfcpdump package, versions *
Threat Intelligence
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Test your applications- Snyk IDSNYK-RHEL10-KERNELZFCPDUMP-19931522
- published19 Sept 2026
- disclosed11 Sept 2026
Introduced: 11 Sep 2026
NewCVE-2026-89557 (opens in a new tab)How to fix?
There is no fixed version for RHEL:10 kernel-zfcpdump.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-zfcpdump package and not the kernel-zfcpdump package as distributed by RHEL.
See How to fix? for RHEL:10 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
md: do overflow check for sb->bblog_shift in super_1_load()
In super_1_load(), sb->bblog_shift is an __u8 type value loaded from on- disk superblock. It is used for badblocks API badblocks_set() by the following sequence,
1930 rdev->badblocks.shift = sb->bblog_shift; 1931 for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) { 1932 u64 bb = le64_to_cpu(*bbp); 1933 int count = bb & (0x3ff); 1934 u64 sector = bb >> 10; 1935 sector <<= sb->bblog_shift; 1936 count <<= sb->bblog_shift; 1937 if (bb + 1 == 0) 1938 break; 1939 if (!badblocks_set(&rdev->badblocks, sector, count, 1)) 1940 return -EINVAL; 1941 }
bb->bblog_shit is in range of 0-255, variable sector is 64bit width, for an invalid bb->bblog_shit, it is possible to make sector be overflowed by the following calculation, 1935 sector <<= sb->bblog_shift; Then in turn when call badblocks_set() at line 1939 with the invalid rdev->badblocks.shift set at line 1930, may result an overflow inside _badblocks_clear() in block/badblocks.c.
Although there are many places to call badblocks APIs, the non-zero shift value is only used in super_1_load(), other places always use 0 as the shift value. Therefore it is unnecessary to do a general shift value overflow check inside badblock API, and just check here as the caller.
This may avoid unnecessary check, make the badblocks API code more simple and elegant.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2532113
- https://access.redhat.com/security/cve/CVE-2026-89557
- https://git.kernel.org/stable/c/35d522bd32462afcf1981dab6da8a9256c26c1e0
- https://git.kernel.org/stable/c/3b097416b4cff77285c1f472fc2c4058d8a7554f
- https://git.kernel.org/stable/c/75d15738fd33a782606d0dc80cfeff47edf2ddd8
- https://git.kernel.org/stable/c/df7d4d011d5ace20699ea948712f09f9ac08924f
- https://git.kernel.org/stable/c/0a03f9541c06fda64301dcf94f376f07ce2cc396
- https://git.kernel.org/stable/c/323f3a056dbccb39a642ebde642044a680f3a6d6
- https://git.kernel.org/stable/c/573fb68105fdc6a127ba6069e58a0d2aff3c9f93
- https://git.kernel.org/stable/c/94c820d99a4305d4ded41a97ed37ec7d26c56e7f