CVE-2026-72193
2026-08-15
06h21 +00:00
06h21 +00:00
Thông báo cho một CVE
Luôn được thông báo về mọi thay đổi đối với một CVE cụ thể.
Mô tả CVE
In the Linux kernel, the following vulnerability has been resolved:
ntfs3: cap RESTART_TABLE free-chain walker at rt->used
A crafted NTFS3 disk image triggers an in-kernel infinite loop at
mount time, hanging the mounting thread and firing the soft-lockup
watchdog within ~22s on multi-CPU hosts (panic with
kernel.softlockup_panic=1). The bug is reachable from desktop USB
auto-mount on distributions where udisks2 routes the NTFS signature
to the in-tree ntfs3 driver (Arch family and an increasing fraction
of Fedora / openSUSE / RHEL deployments); CAP_SYS_ADMIN-class manual
mount elsewhere.
check_rstbl()'s second walker iterates the free-entry singly-linked
list headed by rt->first_free with no upper bound on iteration count:
for (off = ff; off;) {
if (off == RESTART_ENTRY_ALLOCATED)
return false;
off = le32_to_cpu(*(__le32 *)Add2Ptr(rt, off));
if (off > ts - sizeof(__le32))
return false;
}
The existing guards cover three exits: end-of-list (off == 0), the
in-use marker (off == RESTART_ENTRY_ALLOCATED), and out-of-bounds
(off > ts - sizeof(__le32)). None of the three prevents an
in-bounds cycle.
A crafted on-disk RESTART_TABLE whose free chain contains a
self-loop or A->B->A cycle whose offsets satisfy:
- in range [sizeof(struct RESTART_TABLE), ts - sizeof(__le32)]
- (off - sizeof(struct RESTART_TABLE)) % rsize == 0
passes all existing guards and spins the mount-time thread forever.
Reproduced in UML by hand-forging a 2 MB NTFS3 image whose journal
RESTART_TABLE first_free = 0x18 and whose entry at offset 0x18
stores 0x18 as its next pointer; mount of the forged image with
the in-tree ntfs3 driver never returns.
Bound the walker by rt->used. Each entry on a legitimate free
chain is unique, and the total slot count is ne = le16_to_cpu
(rt->used). A traversal that visits more than ne slots is by
construction malformed; reject it as a corrupt RESTART_TABLE.
After this patch, mount of the forged image returns with -EINVAL
and a log_replay failure message, and mkntfs-produced legitimate
images mount cleanly (verified in the same UML harness).
