CVE-2026-89782 is a vulnerability in Linux Kernel
Published on September 16, 2026
fs/ntfs3: reject restart table growth beyond U16_MAX entries
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: reject restart table growth beyond U16_MAX entries
During $LogFile replay, log_replay() indexes the transaction table by the
transact_id taken from the log record header. check_log_rec() only
verifies that transact_id is non-zero and properly aligned, not its
magnitude, so a crafted image can request an arbitrarily large index.
alloc_rsttbl_from_idx() grows the table to cover that index via
extend_rsttbl(), which passes the new entry count to init_rsttbl():
rt = init_rsttbl(esize, used + add);
used + add is computed as u32 but init_rsttbl() takes a u16, and the
count is stored in struct RESTART_TABLE as a __le16. When used + add
exceeds U16_MAX it is truncated, init_rsttbl() allocates a table far
smaller than the index requires, and alloc_rsttbl_from_idx() then
dereferences and writes at the original, untruncated offset -- an
out-of-bounds access past the allocation, reachable by mounting a
crafted NTFS image.
BUG: KASAN: use-after-free in alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950)
Read of size 4 at addr ffff8880327ffff8 by task exploit
alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950)
log_replay (fs/ntfs3/fslog.c:4562)
ntfs_loadlog_and_replay (fs/ntfs3/fsntfs.c:324)
ntfs_fill_super (fs/ntfs3/super.c:1393)
get_tree_bdev_flags
vfs_get_tree
path_mount
__x64_sys_mount
A restart table is limited to U16_MAX entries by its __le16 count, so a
larger growth request is invalid input. Reject it in extend_rsttbl();
all callers already handle a NULL return.
Products Associated with CVE-2026-89782
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Affected Versions
Linux:- Version b46acd6a6a627d876898e1c84d3f84902264b445 and below caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56 is affected.
- Version b46acd6a6a627d876898e1c84d3f84902264b445 and below 339e59996ff193adcf1c438cf05f19e753beb3a7 is affected.
- Version b46acd6a6a627d876898e1c84d3f84902264b445 and below ecde45cd81dc28f5696c312c5ce5a509962e9ab1 is affected.
- Version b46acd6a6a627d876898e1c84d3f84902264b445 and below be218a01aadffe33ed4fc73e25276d676ebbd09d is affected.
- Version b46acd6a6a627d876898e1c84d3f84902264b445 and below aad605a450611e2a7b7cf9dd5724004d39192bfb is affected.
- Version b46acd6a6a627d876898e1c84d3f84902264b445 and below 967a5ff8a614d10126b6d46db1ac040948d6cb42 is affected.
- Version b46acd6a6a627d876898e1c84d3f84902264b445 and below 111f8d74a19d85942ecbb3aba78f6f3c88e59391 is affected.
- Version 5.15 is affected.
- Before 5.15 is unaffected.
- Version 5.15.221, <= 5.15.* is unaffected.
- Version 6.1.188, <= 6.1.* is unaffected.
- Version 6.6.157, <= 6.6.* is unaffected.
- Version 6.12.110, <= 6.12.* is unaffected.
- Version 6.18.52, <= 6.18.* is unaffected.
- Version 7.2.6, <= 7.2.* is unaffected.
- Version 7.3-rc1, <= * is unaffected.