kernel-hacking-2024-linux-s.../fs
Chao Yu 35425ea249 ecryptfs: avoid to access NULL pointer when write metadata in xattr
Christopher Head 2014-06-28 05:26:20 UTC described:
"I tried to reproduce this on 3.12.21. Instead, when I do "echo hello > foo"
in an ecryptfs mount with ecryptfs_xattr specified, I get a kernel crash:

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
PGD d7840067 PUD b2c3c067 PMD 0
Oops: 0002 [#1] SMP
Modules linked in: nvidia(PO)
CPU: 3 PID: 3566 Comm: bash Tainted: P           O 3.12.21-gentoo-r1 #2
Hardware name: ASUSTek Computer Inc. G60JX/G60JX, BIOS 206 03/15/2010
task: ffff8801948944c0 ti: ffff8800bad70000 task.ti: ffff8800bad70000
RIP: 0010:[<ffffffff8110eb39>]  [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
RSP: 0018:ffff8800bad71c10  EFLAGS: 00010246
RAX: 00000000000181a4 RBX: ffff880198648480 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffff880172010450 RDI: 0000000000000000
RBP: ffff880198490e40 R08: 0000000000000000 R09: 0000000000000000
R10: ffff880172010450 R11: ffffea0002c51e80 R12: 0000000000002000
R13: 000000000000001a R14: 0000000000000000 R15: ffff880198490e40
FS:  00007ff224caa700(0000) GS:ffff88019fcc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000bb07f000 CR4: 00000000000007e0
Stack:
ffffffff811826e8 ffff8800a39d8000 0000000000000000 000000000000001a
ffff8800a01d0000 ffff8800a39d8000 ffffffff81185fd5 ffffffff81082c2c
00000001a39d8000 53d0abbc98490e40 0000000000000037 ffff8800a39d8220
Call Trace:
[<ffffffff811826e8>] ? ecryptfs_setxattr+0x40/0x52
[<ffffffff81185fd5>] ? ecryptfs_write_metadata+0x1b3/0x223
[<ffffffff81082c2c>] ? should_resched+0x5/0x23
[<ffffffff8118322b>] ? ecryptfs_initialize_file+0xaf/0xd4
[<ffffffff81183344>] ? ecryptfs_create+0xf4/0x142
[<ffffffff810f8c0d>] ? vfs_create+0x48/0x71
[<ffffffff810f9c86>] ? do_last.isra.68+0x559/0x952
[<ffffffff810f7ce7>] ? link_path_walk+0xbd/0x458
[<ffffffff810fa2a3>] ? path_openat+0x224/0x472
[<ffffffff810fa7bd>] ? do_filp_open+0x2b/0x6f
[<ffffffff81103606>] ? __alloc_fd+0xd6/0xe7
[<ffffffff810ee6ab>] ? do_sys_open+0x65/0xe9
[<ffffffff8157d022>] ? system_call_fastpath+0x16/0x1b
RIP  [<ffffffff8110eb39>] fsstack_copy_attr_all+0x2/0x61
RSP <ffff8800bad71c10>
CR2: 0000000000000000
---[ end trace df9dba5f1ddb8565 ]---"

If we create a file when we mount with ecryptfs_xattr_metadata option, we will
encounter a crash in this path:
->ecryptfs_create
  ->ecryptfs_initialize_file
    ->ecryptfs_write_metadata
      ->ecryptfs_write_metadata_to_xattr
        ->ecryptfs_setxattr
          ->fsstack_copy_attr_all
It's because our dentry->d_inode used in fsstack_copy_attr_all is NULL, and it
will be initialized when ecryptfs_initialize_file finish.

So we should skip copying attr from lower inode when the value of ->d_inode is
invalid.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Cc: stable@vger.kernel.org # v3.2+: b59db43 eCryptfs: Prevent file create race condition
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2014-10-05 23:51:43 -05:00
..
9p consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
adfs adfs: delayed freeing of sbi 2013-10-24 23:43:27 -04:00
affs remove obsolete references to powertweak 2013-11-27 20:34:32 -08:00
afs Merge branch 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into linux-next 2013-10-28 19:36:46 -04:00
autofs4 autofs4: make freeing sbi rcu-delayed 2013-10-24 23:43:27 -04:00
befs befs: split symlink iops in two - for short and long symlinks resp. 2013-10-24 23:34:50 -04:00
bfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2013-12-12 15:25:10 -08:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
ceph Merge branch 'for-linus-bugs' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2013-11-26 18:02:46 -08:00
cifs [CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload 2013-11-25 09:50:31 -06:00
coda coda_revalidate_inode(): switch to passing inode... 2013-11-09 00:16:21 -05:00
configfs configfs: fix race between dentry put and lookup 2013-11-21 16:42:27 -08:00
cramfs cramfs: mark as obsolete 2013-11-13 12:09:12 +09:00
debugfs debugfs: use list_next_entry() in debugfs_remove_recursive() 2013-11-13 12:09:24 +09:00
devpts devpts: plug the memory leak in kill_sb 2013-11-13 12:09:36 +09:00
dlm genetlink: only pass array to genl_register_family_with_ops() 2013-11-19 16:39:05 -05:00
ecryptfs ecryptfs: avoid to access NULL pointer when write metadata in xattr 2014-10-05 23:51:43 -05:00
efivarfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
efs
exofs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
exportfs exportfs: fix quadratic behavior in filehandle lookup 2013-11-09 00:16:38 -05:00
ext2 ext2: Fix fs corruption in ext2_get_xip_mem() 2013-11-05 11:26:47 +01:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2013-11-13 15:25:47 +09:00
ext4 Ext4 updates for 3.13. Mostly bug fixes and cleanups. 2013-11-14 17:19:58 +09:00
f2fs f2fs: issue more large discard command 2013-11-11 09:36:32 +09:00
fat fat: rcu-delay unloading nls and freeing sbi 2013-10-24 23:43:28 -04:00
freevxfs
fscache Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
gfs2 GFS2: Fix ref count bug relating to atomic_open 2013-11-21 18:47:57 +00:00
hfs fs/hfs/btree.h: remove duplicate defines 2013-11-13 12:09:32 +09:00
hfsplus block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
hostfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
hpfs locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
hppfs
hugetlbfs
isofs isofs: don't pass dentry to isofs_hash{i,}_common() 2013-10-24 23:34:59 -04:00
jbd jbd: Revert "jbd: remove dependency on __GFP_NOFAIL" 2013-10-31 20:37:15 +01:00
jbd2
jffs2 jffs2: do not support the MLC nand 2013-10-27 16:27:07 -07:00
jfs Just a patch to fix an oops in an error path. 2013-10-22 09:01:11 +01:00
lockd
logfs block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
minix fs/minix: Drop dependency on H8300 2013-09-16 18:20:25 -07:00
ncpfs ncpfs: rcu-delay unload_nls() and freeing ncp_server 2013-10-24 23:43:28 -04:00
nfs NFS client bugfixes 2013-12-05 13:05:48 -08:00
nfs_common
nfsd nfsd: when reusing an existing repcache entry, unhash it first 2013-12-10 20:34:44 -05:00
nilfs2 nilfs2: fix issue with race condition of competition between segments for dirty blocks 2013-09-30 14:31:02 -07:00
nls
notify
ntfs iget/iget5: don't bother with ->i_lock until we find a match 2013-11-09 00:16:31 -05:00
ocfs2 tree-wide: use reinit_completion instead of INIT_COMPLETION 2013-11-15 09:32:21 +09:00
omfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
openpromfs
proc procfs: also fix proc_reg_get_unmapped_area() for !MMU case 2013-12-12 18:19:26 -08:00
pstore pstore: Remove the messages related to compression failure 2013-09-16 09:28:29 -07:00
qnx4 qnx4: i_sb is never NULL 2013-11-09 00:16:32 -05:00
qnx6
quota genetlink: make multicast groups const, prevent abuse 2013-11-19 16:39:06 -05:00
ramfs initmpfs: move rootfs code from fs/ramfs/ to init/ 2013-09-11 15:59:37 -07:00
reiserfs reiserfs: fix race with flush_used_journal_lists and flush_journal_list 2013-09-24 11:24:21 +02:00
romfs
squashfs Squashfs: fix failure to unlock pages on decompress error 2013-11-24 01:02:50 +00:00
sysfs Revert "sysfs: handle duplicate removal attempts in sysfs_remove_group()" 2013-11-27 09:44:55 -08:00
sysv sysv: Add forgotten superblock lock init for v7 fs 2013-09-29 22:02:02 -04:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
udf udf: fix for pathetic mount times in case of invalid file system 2013-10-18 22:39:07 +02:00
ufs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
xfs xfs: growfs overruns AGFL buffer on V4 filesystems 2013-12-10 10:04:27 -06:00
aio.c Merge git://git.kvack.org/~bcrl/aio-next 2013-12-06 08:32:59 -08:00
anon_inodes.c ... and kill anon_inode_getfile_private() 2013-11-09 00:16:28 -05:00
attr.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
bad_inode.c
binfmt_aout.c dump_skip(): dump_seek() replacement taking coredump_params 2013-11-09 00:16:26 -05:00
binfmt_elf.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -05:00
binfmt_elf_fdpic.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -05:00
binfmt_em86.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c Merge branch 'for-3.12/core' of git://git.kernel.dk/linux-block 2013-09-22 15:00:11 -07:00
bio.c bio: fix argument of __bio_add_page() for max_sectors > 0xffff 2013-11-18 12:31:27 -07:00
block_dev.c a trivial writeback fix 2013-09-13 23:06:40 -04:00
buffer.c fs: buffer: move allocation failure loop into the allocator 2013-10-16 21:35:53 -07:00
char_dev.c Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
compat.c
compat_binfmt_elf.c
compat_ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
coredump.c dump_emit(): use __kernel_write(), not vfs_write() 2013-11-15 22:04:09 -05:00
coredump.h
dcache.c dcache: allow word-at-a-time name hashing with big-endian CPUs 2013-12-12 10:39:01 -08:00
dcookies.c
direct-io.c direct-io: Use return from cmpxchg to decide of assignment happened 2013-09-09 10:47:42 -07:00
drop_caches.c shrinker: add node awareness 2013-09-10 18:56:31 -04:00
eventfd.c
eventpoll.c epoll: drop EPOLLWAKEUP if PM_SLEEP is disabled 2013-12-03 15:35:52 +01:00
exec.c Merge git://git.infradead.org/users/eparis/audit 2013-11-21 19:18:14 -08:00
fcntl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
fhandle.c
file.c
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
filesystems.c
fs-writeback.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
fs_struct.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
generic_acl.c
inode.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
internal.h get rid of s_files and files_lock 2013-11-09 00:16:20 -05:00
ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
locks.c locks: missing unlock on error in generic_add_lease() 2013-11-13 07:30:53 -05:00
Makefile
mbcache.c fs: convert fs shrinkers to new scan/count API 2013-09-10 18:56:31 -04:00
mount.h RCU'd vfsmounts 2013-11-09 00:16:19 -05:00
mpage.c
namei.c dcache: allow word-at-a-time name hashing with big-endian CPUs 2013-12-12 10:39:01 -08:00
namespace.c RCU'd vfsmounts 2013-11-09 00:16:19 -05:00
no-block.c
open.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
pipe.c vfs: fix subtle use-after-free of pipe_inode_info 2013-12-02 09:44:51 -08:00
pnode.c split __lookup_mnt() in two functions 2013-10-24 23:35:00 -04:00
pnode.h
posix_acl.c
proc_namespace.c don't bother with vfsmount_lock in mounts_poll() 2013-10-24 23:34:59 -04:00
read_write.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
readdir.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
select.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
seq_file.c seq_file: always clear m->count when we free m->buf 2013-11-18 19:07:53 -08:00
signalfd.c
splice.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
stack.c
stat.c vfs: split out vfs_getattr_nosec 2013-11-09 00:16:31 -05:00
statfs.c vfs: allow O_PATH file descriptors for fstatfs() 2013-10-12 13:12:31 -07:00
super.c get rid of s_files and files_lock 2013-11-09 00:16:20 -05:00
sync.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
timerfd.c
utimes.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
xattr.c
xattr_acl.c