4.19-stable review patch. If anyone has any objections, please let me know.
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From: Greg Kroah-Hartman gregkh@linuxfoundation.org
commit 7c55b78818cfb732680c4a72ab270cc2d2ee3d0f upstream.
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 shaggy@kernel.org Link: https://lore.kernel.org/r/2024051433-slider-cloning-98f9@gregkh Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/jfs/xattr.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/jfs/xattr.c +++ b/fs/jfs/xattr.c @@ -570,9 +570,11 @@ static int ea_get(struct inode *inode, s
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;