On 10/5/24 5:06AM, Artem Sadovnikov wrote:

Commit 7c55b78818cf ("jfs: xattr: fix buffer overflow for invalid xattr") also addresses this issue but it only fixes it for positive values, while ea_size is an integer type and can take negative values, e.g. in case of a corrupted filesystem. This still breaks validation and would overflow because of implicit conversion from int to size_t in print_hex_dump().

Fix this issue by clamping the ea_size value instead.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Cc: stable@vger.kernel.org Signed-off-by: Artem Sadovnikov ancowi69@gmail.com

Looks good. I'll apply this one.

Shaggy

---

fs/jfs/xattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c index 8ef8dfc3c194..95bcbbf7359c 100644 --- a/fs/jfs/xattr.c +++ b/fs/jfs/xattr.c @@ -557,7 +557,7 @@ static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size) size_check: if (EALIST_SIZE(ea_buf->xattr) != ea_size) {

• int size = min_t(int, EALIST_SIZE(ea_buf->xattr), ea_size);
  

• int size = clamp_t(int, ea_size, 0, EALIST_SIZE(ea_buf->xattr));
  

printk(KERN_ERR "ea_get: invalid extended attribute\n"); print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,