From 7c55b78818cfb732680c4a72ab270cc2d2ee3d0f Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 14 May 2024 12:06:34 +0200 Subject: 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: syzbot+9dfe490c8176301c1d06@syzkaller.appspotmail.com Cc: Dave Kleikamp Link: https://lore.kernel.org/r/2024051433-slider-cloning-98f9@gregkh Signed-off-by: Greg Kroah-Hartman --- fs/jfs/xattr.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c index 0fb7afac298e..9987055293b3 100644 --- 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; -- cgit v1.2.3