This is a note to let you know that I've just added the patch titled afs: Fix incorrect freeing of the ACL passed to the YFS ACL store op to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: afs-fix-incorrect-freeing-of-the-acl-passed-to-the-y.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e9eb47d199f56aa893dff7ffe8194fce632b4131 Author: David Howells <dhowells@xxxxxxxxxx> Date: Tue Nov 3 16:33:07 2020 +0000 afs: Fix incorrect freeing of the ACL passed to the YFS ACL store op [ Upstream commit f4c79144edd8a49ffca8fa737a31d606be742a34 ] 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@xxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c index 38884d6c57cdc..95c573dcda116 100644 --- a/fs/afs/xattr.c +++ b/fs/afs/xattr.c @@ -148,11 +148,6 @@ static const struct xattr_handler afs_xattr_afs_acl_handler = { .set = afs_xattr_set_acl, }; -static void yfs_acl_put(struct afs_operation *op) -{ - yfs_free_opaque_acl(op->yacl); -} - static const struct afs_operation_ops yfs_fetch_opaque_acl_operation = { .issue_yfs_rpc = yfs_fs_fetch_opaque_acl, .success = afs_acl_success, @@ -246,7 +241,7 @@ error: static const struct afs_operation_ops yfs_store_opaque_acl2_operation = { .issue_yfs_rpc = yfs_fs_store_opaque_acl2, .success = afs_acl_success, - .put = yfs_acl_put, + .put = afs_acl_put, }; /*