jfs: xattr: fix buffer overflow for invalid xattr

When an xattr size is not what is expected, it is printed out to the kernel log in hex format as a form of debugging. But when that xattr size is bigger than the expected size, printing it out can cause an access off the end of the buffer. Fix this all up by properly restricting the size of the debug hex dump in the kernel log. Reported-by: [email protected] Cc: Dave Kleikamp <[email protected]> Link: https://lore.kernel.org/r/2024051433-slider-cloning-98f9@gregkh Signed-off-by: Greg Kroah-Hartman <[email protected]>
multipath-tcp · Jun 4, 2024 · 7c55b78 · 7c55b78
1 parent 77427e3
commit 7c55b78
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
@@ -557,9 +557,11 @@ 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);
+
 		printk(KERN_ERR "ea_get: invalid extended attribute\n");
 		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
-				     ea_buf->xattr, ea_size, 1);
+				     ea_buf->xattr, size, 1);
 		ea_release(inode, ea_buf);
 		rc = -EIO;
 		goto clean_up;