From 8aa32dd61fce0411ae3fae18cd62f77b85b96495 Mon Sep 17 00:00:00 2001 From: Artem Sadovnikov Date: Sat, 5 Oct 2024 10:06:57 +0000 Subject: [PATCH] jfs: xattr: check invalid xattr size more strictly commit d9f9d96136cba8fedd647d2c024342ce090133c2 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- 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 64fc5263d..e37761fe2 100755 --- 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,