[PATCH AUTOSEL 7.0-6.1] ntfs3: fix OOB write in attr_wof_frame_info()

Sasha Levin
2026-04-28T10:42:44Z

From: 0xkato <0xkkato@gmail.com>

[ Upstream commit 859d777646b56dd878b136392f3d03fb8153b559 ]

In attr_wof_frame_info(), the offset-table read range for a nonresident
WofCompressedData stream is:

u64 from = vbo[i] & ~(u64)(PAGE_SIZE - 1);
u64 to = min(from + PAGE_SIZE, wof_size);
...
ntfs_read_run(sbi, run, addr, from, to - from);

A crafted image sets WofCompressedData.nres.data_size to 0xfff while the
file is large enough to request frame 1024 (offset 0x400000). This gives
from=0x1000, to=0xfff. The unsigned (to - from) wraps to 0xffffffffffffffff
and ntfs_read_write_run() overflows the single-page offs_folio via memcpy.

Triggered by pread() on a mounted NTFS image. Depending on adjacent
memory layout at the time of the overflow, KASAN reports this as
slab-out-of-bounds, use-after-free, or slab-use-after-free all at
ntfs_read_write_run(). Secondary corruption/panic paths were also observed.

Reject the read when the offset-table page is outside the stream.

Signed-off-by: 0xkato <0xkkato@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

fs/ntfs3/attrib.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index 6cb9bc5d605c2..89921e5091c9a 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -1576,6 +1576,12 @@ int attr_wof_frame_info(struct ntfs_inode *ni, struct ATTRIB *attr,
u64 from = vbo[i] & ~(u64)(PAGE_SIZE - 1);
u64 to = min(from + PAGE_SIZE, wof_size);

+ if (from >= wof_size) {
+ _ntfs_bad_inode(&ni->vfs_inode);
+ err = -EINVAL;
+ goto out1;
+ }
+
err = attr_load_runs_range(ni, ATTR_DATA, WOF_NAME,
ARRAY_SIZE(WOF_NAME), run,
from, to);
--
2.53.0