From: Artem Sadovnikov Date: Sat, 5 Oct 2024 10:06:57 +0000 (+0000) Subject: jfs: xattr: check invalid xattr size more strictly X-Git-Tag: v6.13-rc1~128^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d9f9d96136cba8fedd647d2c024342ce090133c2;p=thirdparty%2Fkernel%2Flinux.git jfs: xattr: check invalid xattr size more strictly 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 Signed-off-by: Dave Kleikamp --- diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c index 0fb05e314edf6..24afbae87225a 100644 --- a/fs/jfs/xattr.c +++ b/fs/jfs/xattr.c @@ -559,7 +559,7 @@ 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,