afs: Fix incorrect freeing of the ACL passed to the YFS ACL store op
authorDavid Howells <dhowells@redhat.com>
Tue, 3 Nov 2020 16:33:07 +0000 (16:33 +0000)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 3 Nov 2020 17:53:40 +0000 (09:53 -0800)
commitf4c79144edd8a49ffca8fa737a31d606be742a34
tree310efa7208d15049815e64947adec1540638ad53
parentc80afa1d9c3603d5eddeb8d63368823b1982f3f0
afs: Fix incorrect freeing of the ACL passed to the YFS ACL store op

The cleanup for the yfs_store_opaque_acl2_operation calls the wrong
function to destroy the ACL content buffer.  It's an afs_acl struct, not
a yfs_acl struct - and the free function for latter may pass invalid
pointers to kfree().

Fix this by using the afs_acl_put() function.  The yfs_acl_put()
function is then no longer used and can be removed.

general protection fault, probably for non-canonical address 0x7ebde00000000: 0000 [#1] SMP PTI
...
RIP: 0010:compound_head+0x0/0x11
...
Call Trace:
 virt_to_cache+0x8/0x51
 kfree+0x5d/0x79
 yfs_free_opaque_acl+0x16/0x29
 afs_put_operation+0x60/0x114
 __vfs_setxattr+0x67/0x72
 __vfs_setxattr_noperm+0x66/0xe9
 vfs_setxattr+0x67/0xce
 setxattr+0x14e/0x184
 __do_sys_fsetxattr+0x66/0x8f
 do_syscall_64+0x2d/0x3a
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/afs/xattr.c