CVE-2026-89782
Received
Received - Intake
Buffer Overflow in Linux Kernel NTFS3 Filesystem
Vulnerability report for CVE-2026-89782, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-16
Last updated on: 2026-09-16
Assigner: kernel.org
Description
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
| linux_kernel | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
