linux-brain/fs
Lior Ribak c0e0ab60d0 binfmt_misc: fix possible deadlock in bm_register_write
commit e7850f4d844e0acfac7e570af611d89deade3146 upstream.

There is a deadlock in bm_register_write:

First, in the begining of the function, a lock is taken on the binfmt_misc
root inode with inode_lock(d_inode(root)).

Then, if the user used the MISC_FMT_OPEN_FILE flag, the function will call
open_exec on the user-provided interpreter.

open_exec will call a path lookup, and if the path lookup process includes
the root of binfmt_misc, it will try to take a shared lock on its inode
again, but it is already locked, and the code will get stuck in a deadlock

To reproduce the bug:
$ echo ":iiiii:E::ii::/proc/sys/fs/binfmt_misc/bla:F" > /proc/sys/fs/binfmt_misc/register

backtrace of where the lock occurs (#5):
0  schedule () at ./arch/x86/include/asm/current.h:15
1  0xffffffff81b51237 in rwsem_down_read_slowpath (sem=0xffff888003b202e0, count=<optimized out>, state=state@entry=2) at kernel/locking/rwsem.c:992
2  0xffffffff81b5150a in __down_read_common (state=2, sem=<optimized out>) at kernel/locking/rwsem.c:1213
3  __down_read (sem=<optimized out>) at kernel/locking/rwsem.c:1222
4  down_read (sem=<optimized out>) at kernel/locking/rwsem.c:1355
5  0xffffffff811ee22a in inode_lock_shared (inode=<optimized out>) at ./include/linux/fs.h:783
6  open_last_lookups (op=0xffffc9000022fe34, file=0xffff888004098600, nd=0xffffc9000022fd10) at fs/namei.c:3177
7  path_openat (nd=nd@entry=0xffffc9000022fd10, op=op@entry=0xffffc9000022fe34, flags=flags@entry=65) at fs/namei.c:3366
8  0xffffffff811efe1c in do_filp_open (dfd=<optimized out>, pathname=pathname@entry=0xffff8880031b9000, op=op@entry=0xffffc9000022fe34) at fs/namei.c:3396
9  0xffffffff811e493f in do_open_execat (fd=fd@entry=-100, name=name@entry=0xffff8880031b9000, flags=<optimized out>, flags@entry=0) at fs/exec.c:913
10 0xffffffff811e4a92 in open_exec (name=<optimized out>) at fs/exec.c:948
11 0xffffffff8124aa84 in bm_register_write (file=<optimized out>, buffer=<optimized out>, count=19, ppos=<optimized out>) at fs/binfmt_misc.c:682
12 0xffffffff811decd2 in vfs_write (file=file@entry=0xffff888004098500, buf=buf@entry=0xa758d0 ":iiiii:E::ii::i:CF
", count=count@entry=19, pos=pos@entry=0xffffc9000022ff10) at fs/read_write.c:603
13 0xffffffff811defda in ksys_write (fd=<optimized out>, buf=0xa758d0 ":iiiii:E::ii::i:CF
", count=19) at fs/read_write.c:658
14 0xffffffff81b49813 in do_syscall_64 (nr=<optimized out>, regs=0xffffc9000022ff58) at arch/x86/entry/common.c:46
15 0xffffffff81c0007c in entry_SYSCALL_64 () at arch/x86/entry/entry_64.S:120

To solve the issue, the open_exec call is moved to before the write
lock is taken by bm_register_write

Link: https://lkml.kernel.org/r/20210228224414.95962-1-liorribak@gmail.com
Fixes: 948b701a60 ("binfmt_misc: add persistent opened binary handler for containers")
Signed-off-by: Lior Ribak <liorribak@gmail.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:03:57 +01:00
..
9p 9P: Cast to loff_t before multiplying 2020-11-05 11:43:34 +01:00
adfs Merge branch 'work.adfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 11:33:22 -07:00
affs fs/affs: release old buffer head on error path 2021-03-04 10:26:48 +01:00
afs rxrpc: Fix deadlock around release of dst cached on udp tunnel 2021-02-10 09:25:27 +01:00
autofs autofs: fix a leak in autofs_expire_indirect() 2019-10-25 00:03:11 -04:00
befs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
bfs bfs: don't use WARNING: string when it's just info. 2021-01-06 14:48:39 +01:00
btrfs btrfs: fix warning when creating a directory with smack enabled 2021-03-09 11:09:37 +01:00
cachefiles cachefiles: Handle readpage error correctly 2020-11-05 11:43:36 +01:00
ceph ceph: fix race in concurrent __ceph_remove_cap invocations 2020-12-30 11:51:40 +01:00
cifs cifs: return proper error code in statfs(2) 2021-03-17 17:03:34 +01:00
coda y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
configfs configfs: fix a use-after-free in __configfs_open_file 2021-03-17 17:03:56 +01:00
cramfs cramfs: fix usage on non-MTD device 2019-11-23 21:44:49 -05:00
crypto fscrypt: remove kernel-internal constants from UAPI header 2021-01-06 14:48:35 +01:00
debugfs debugfs: do not attempt to create a new file before the filesystem is initalized 2021-03-04 10:26:10 +01:00
devpts devpts_pty_kill(): don't bother with d_delete() 2019-09-03 09:30:56 -04:00
dlm fs: dlm: fix configfs memory leak 2020-10-29 09:58:03 +01:00
ecryptfs ecryptfs: replace BUG_ON with error handling code 2020-02-28 17:22:26 +01:00
efivarfs efivarfs: revert "fix memory leak in efivarfs_create()" 2020-12-02 08:49:53 +01:00
efs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
erofs erofs: fix shift-out-of-bounds of blkszbits 2021-03-07 12:20:42 +01:00
exportfs exportfs_decode_fh(): negative pinned may become positive without the parent locked 2019-11-10 11:56:05 -05:00
ext2 ext2: don't update mtime on COW faults 2020-09-09 19:12:30 +02:00
ext4 ext4: fix potential htree index checksum corruption 2021-03-04 10:26:37 +01:00
f2fs f2fs: fix to set/clear I_LINKABLE under i_lock 2021-03-07 12:20:46 +01:00
fat fat: don't allow to mount if the FAT length == 0 2020-06-17 16:40:36 +02:00
freevxfs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
fscache Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
fuse fuse: fix bad inode 2021-01-09 13:44:54 +01:00
gfs2 gfs2: Recursive gfs2_quota_hold in gfs2_iomap_end 2021-03-04 10:26:51 +01:00
hfs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
hfsplus hfsplus: fix crash and filesystem corruption when deleting files 2020-04-17 10:50:22 +02:00
hostfs
hpfs fs: hpfs: Initialize filesystem timestamp ranges 2019-08-30 08:11:25 -07:00
hugetlbfs mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page 2021-02-10 09:25:31 +01:00
iomap iomap: fix WARN_ON_ONCE() from unprivileged users 2020-10-29 09:58:06 +01:00
isofs isofs: release buffer head before return 2021-03-04 10:26:30 +01:00
jbd2 jbd2: fix up sparse warnings in checkpoint code 2020-11-18 19:20:30 +01:00
jffs2 jffs2: fix use after free in jffs2_sum_write_data() 2021-03-04 10:26:25 +01:00
jfs JFS: more checks for invalid superblock 2021-03-07 12:20:41 +01:00
kernfs kernfs: do not call fsnotify() with name without a parent 2020-08-19 08:16:12 +02:00
lockd lockd: don't use interval-based rebinding over TCP 2020-12-30 11:51:16 +01:00
minix fs/minix: remove expected error message in block_to_path() 2020-08-21 13:05:37 +02:00
nfs NFSv4.2: fix return value of _nfs4_get_security_label() 2021-03-17 17:03:56 +01:00
nfs_common nfs_common: need lock during iterate through the list 2020-12-30 11:51:22 +01:00
nfsd nfsd: register pernet ops last, unregister first 2021-03-04 10:26:34 +01:00
nilfs2 nilfs2: fix null pointer dereference at nilfs_segctor_do_construct() 2020-06-17 16:40:29 +02:00
nls treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
notify fanotify: fix ignore mask logic for events on child and on dir 2020-06-17 16:40:24 +02:00
ntfs ntfs: check for valid standard information attribute 2021-02-26 10:10:27 +01:00
ocfs2 ocfs2: fix a use after free on error 2021-03-04 10:26:39 +01:00
omfs fs: omfs: Initialize filesystem timestamp ranges 2019-08-30 08:11:25 -07:00
openpromfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
orangefs orangefs: get rid of knob code... 2020-08-21 13:05:29 +02:00
overlayfs ovl: expand warning in ovl_d_real() 2021-02-17 10:35:19 +01:00
proc proc: fix lookup in /proc/net subdirectories after setns(2) 2021-01-12 20:16:10 +01:00
pstore pstore: Fix typo in compression option name 2021-03-04 10:26:45 +01:00
qnx4 fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
qnx6 fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
quota quota: Fix memory leak when handling corrupted quota file 2021-03-04 10:26:26 +01:00
ramfs ramfs: fix nommu mmap with gaps in the page cache 2020-10-29 09:57:53 +01:00
reiserfs reiserfs: add check for an invalid ih_entry_count 2021-01-06 14:48:38 +01:00
romfs romfs: fix uninitialized memory leak in romfs_dev_read() 2020-08-26 10:40:51 +02:00
squashfs squashfs: add more sanity checks in xattr id lookup 2021-02-13 13:52:57 +01:00
sysfs sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output 2021-03-07 12:20:48 +01:00
sysv fs: sysv: Initialize filesystem timestamp ranges 2019-08-30 07:27:18 -07:00
tracefs tracing: Do not create tracefs files if tracefs lockdown is in effect 2019-10-12 20:49:07 -04:00
ubifs ubifs: Fix error return code in alloc_wbufs() 2021-03-04 10:26:26 +01:00
udf udf: fix silent AED tagLocation corruption 2021-03-17 17:03:41 +01:00
ufs fs/ufs: avoid potential u32 multiplication overflow 2020-08-21 13:05:37 +02:00
unicode unicode: make array 'token' static const, makes object smaller 2019-09-17 11:48:24 -04:00
verity fs-verity: support builtin file signatures 2019-08-12 19:33:50 -07:00
xfs xfs: Fix assert failure in xfs_setattr_size() 2021-03-07 12:20:42 +01:00
aio.c aio: fix async fsync creds 2020-06-17 16:40:24 +02:00
anon_inodes.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
attr.c utimes: Clamp the timestamps in notify_change() 2020-02-11 04:35:12 -08:00
bad_inode.c
binfmt_aout.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
binfmt_elf_fdpic.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
binfmt_elf.c fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info() 2020-06-03 08:21:27 +02:00
binfmt_em86.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
binfmt_flat.c binfmt_flat: revert "binfmt_flat: don't offset the data start" 2020-09-03 11:26:39 +02:00
binfmt_misc.c binfmt_misc: fix possible deadlock in bm_register_write 2021-03-17 17:03:57 +01:00
binfmt_script.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
block_dev.c bdev: Reduce time holding bd_mutex in sync in blkdev_close() 2020-10-01 13:17:55 +02:00
buffer.c fs: Don't invalidate page buffers in block_write_full_page() 2020-11-05 11:43:24 +01:00
char_dev.c chardev: Avoid potential use-after-free in 'chrdev_open()' 2020-01-14 20:08:18 +01:00
compat_binfmt_elf.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
compat_ioctl.c fix compat handling of FICLONERANGE, FIDEDUPERANGE and FS_IOC_FIEMAP 2020-01-09 10:20:05 +01:00
compat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
coredump.c coredump: fix core_pattern parse error 2020-12-11 13:23:30 +01:00
d_path.c fs: fix NULL dereference due to data race in prepend_path() 2020-10-29 09:57:45 +01:00
dax.c mm: provide a saner PTE walking API for modules 2021-02-26 10:10:28 +01:00
dcache.c fix dget_parent() fastpath race 2020-10-01 13:17:19 +02:00
dcookies.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
direct-io.c fs/direct-io.c: fix kernel-doc warning 2019-10-14 15:04:01 -07:00
drop_caches.c fs: avoid softlockups in s_inodes iterators 2020-01-12 12:21:37 +01:00
eventfd.c eventfd: track eventfd_signal() recursion depth 2020-02-11 04:35:37 -08:00
eventpoll.c ep_create_wakeup_source(): dentry name can change under you... 2020-10-07 08:01:31 +02:00
exec.c exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:44:55 +01:00
fcntl.c fcntl: Fix potential deadlock in send_sig{io, urg}() 2021-01-06 14:48:39 +01:00
fhandle.c fs/handle.c - fix up kerneldoc 2019-08-07 21:51:47 -04:00
file_table.c vfs: Export flush_delayed_fput for use by knfsd. 2019-08-19 11:00:39 -04:00
file.c fix multiplication overflow in copy_fdtable() 2020-05-27 17:46:12 +02:00
filesystems.c fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once() 2020-04-17 10:50:21 +02:00
fs_context.c vfs: subtype handling moved to fuse 2019-09-06 21:28:49 +02:00
fs_parser.c vfs: Make fs_parse() handle fs_param_is_fd-type params better 2019-09-12 21:06:14 -04:00
fs_pin.c switch the remnants of releasing the mountpoint away from fs_pin 2019-07-16 22:52:37 -04:00
fs_struct.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
fs_types.c
fs-writeback.c fs: fix lazytime expiration handling in __writeback_single_inode() 2021-01-30 13:54:11 +01:00
fsopen.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
inode.c futex: Fix inode life-time issue 2020-03-25 08:25:58 +01:00
internal.h fs: move guard_bio_eod() after bio_set_op_attrs 2020-01-17 19:48:21 +01:00
io_uring.c io_uring: Fix current->fs handling in io_sq_wq_submit_work() 2021-01-30 13:54:10 +01:00
ioctl.c compat_ioctl: add compat_ptr_ioctl() 2019-12-17 19:55:30 +01:00
Kconfig fs-verity for 5.4 2019-09-18 16:59:14 -07:00
Kconfig.binfmt binfmt_flat: make support for old format binaries optional 2019-06-24 09:16:47 +10:00
libfs.c libfs: fix error cast of negative value in simple_attr_write() 2020-11-24 13:29:19 +01:00
locks.c locks: reinstate locks_delete_block optimization 2020-03-25 08:25:41 +01:00
Makefile fs-verity for 5.4 2019-09-18 16:59:14 -07:00
mbcache.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
mount.h switch the remnants of releasing the mountpoint away from fs_pin 2019-07-16 22:52:37 -04:00
mpage.c fs: move guard_bio_eod() after bio_set_op_attrs 2020-01-17 19:48:21 +01:00
namei.c namei: only return -ECHILD from follow_dotdot_rcu() 2020-03-05 16:43:48 +01:00
namespace.c fs/namespace.c: WARN if mnt_count has become negative 2021-01-06 14:48:40 +01:00
no-block.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
nsfs.c vfs: Convert nsfs to use the new mount API 2019-05-25 18:00:06 -04:00
open.c cifs_atomic_open(): fix double-put on late allocation failure 2020-03-18 07:17:51 +01:00
pipe.c vfs: Convert pipe to use the new mount API 2019-05-25 18:00:07 -04:00
pnode.c propagate_one(): mnt_set_mountpoint() needs mount_lock 2020-05-02 08:48:44 +02:00
pnode.h mount: fix mounting of detached mounts onto targets that reside on shared mounts 2021-03-17 17:03:33 +01:00
posix_acl.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
proc_namespace.c vfs: subtype handling moved to fuse 2019-09-06 21:28:49 +02:00
read_write.c fs: allow deduplication of eof block into the end of the destination file 2020-02-11 04:35:23 -08:00
readdir.c readdir: be more conservative with directory entry names 2020-01-29 16:45:31 +01:00
select.c fs/select.c: use struct_size() in kmalloc() 2019-07-16 19:23:25 -07:00
seq_file.c seq_file: fix problem when seeking mid-record 2019-08-13 16:06:52 -07:00
signalfd.c fs/signalfd.c: fix inconsistent return codes for signalfd4 2020-08-26 10:40:58 +02:00
splice.c splice: only read in as much information as there is pipe buffer space 2019-12-17 19:56:52 +01:00
stack.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
stat.c
statfs.c vfs: Fix EOVERFLOW testing in put_compat_statfs64 2019-10-03 14:21:35 -07:00
super.c vfs: remove lockdep bogosity in __sb_start_write 2020-11-24 13:29:01 +01:00
sync.c
timerfd.c timerfd: Prepare for PREEMPT_RT 2019-08-01 20:51:23 +02:00
userfaultfd.c userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK 2020-01-04 19:18:32 +01:00
utimes.c utimes: Clamp the timestamps in notify_change() 2020-02-11 04:35:12 -08:00
xattr.c xattr: break delegations in {set,remove}xattr 2020-08-11 15:33:39 +02:00