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tmp_suning_uos_patched/fs
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Davide Libenzi 22bacca48a epoll: prevent creating circular epoll structures 
In several places, an epoll fd can call another file's ->f_op->poll()
method with ep->mtx held.  This is in general unsafe, because that other
file could itself be an epoll fd that contains the original epoll fd.

The code defends against this possibility in its own ->poll() method using
ep_call_nested, but there are several other unsafe calls to ->poll
elsewhere that can be made to deadlock.  For example, the following simple
program causes the call in ep_insert recursively call the original fd's
->poll, leading to deadlock:

 #include <unistd.h>
 #include <sys/epoll.h>

 int main(void) {
     int e1, e2, p[2];
     struct epoll_event evt = {
         .events = EPOLLIN
     };

     e1 = epoll_create(1);
     e2 = epoll_create(2);
     pipe(p);

     epoll_ctl(e2, EPOLL_CTL_ADD, e1, &evt);
     epoll_ctl(e1, EPOLL_CTL_ADD, p[0], &evt);
     write(p[1], p, sizeof p);
     epoll_ctl(e1, EPOLL_CTL_ADD, e2, &evt);

     return 0;
 }

On insertion, check whether the inserted file is itself a struct epoll,
and if so, do a recursive walk to detect whether inserting this file would
create a loop of epoll structures, which could lead to deadlock.

[nelhage@ksplice.com: Use epmutex to serialize concurrent inserts]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Reported-by: Nelson Elhage <nelhage@ksplice.com>
Tested-by: Nelson Elhage <nelhage@ksplice.com>
Cc: <stable@kernel.org>		[2.6.34+, possibly earlier]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-25 15:07:36 -08:00
..
9p switch 9p 2011-01-12 20:03:43 -05:00
adfs switch adfs 2011-01-12 20:02:45 -05:00
affs switch affs 2011-01-12 20:03:42 -05:00
afs afs: Fix oops in afs_unlink_writeback 2011-02-25 11:12:37 -08:00
autofs4 autofs4: clean ->d_release() and autofs4_free_ino() up 2011-01-18 01:21:29 -05:00
befs befs: don't pass huge structs by value 2011-01-13 08:03:15 -08:00
bfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
btrfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable 2011-02-25 14:03:39 -08:00
cachefiles
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2011-02-21 15:01:38 -08:00
cifs [CIFS] update cifs version 2011-02-21 22:31:47 +00:00
coda Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-01-13 10:27:28 -08:00
configfs configfs: change depends -> select SYSFS 2011-01-16 21:22:29 +00:00
cramfs cramfs: generate unique inode number for better inode cache usage 2011-01-13 08:03:23 -08:00
debugfs
devpts
dlm dlm: use single thread workqueues 2011-02-11 16:50:47 -06:00
ecryptfs eCryptfs: Copy up lower inode attrs in getattr 2011-02-21 14:46:36 -06:00
efs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
exofs Revert "exofs: Set i_mapping->backing_dev_info anyway" 2011-02-02 17:53:27 -08:00
exportfs fs: dcache per-inode inode alias locking 2011-01-07 17:50:31 +11:00
ext2 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2011-01-11 14:37:31 -08:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 2011-01-21 07:33:37 -08:00
ext4 ext4: serialize unaligned asynchronous DIO 2011-02-12 08:17:34 -05:00
fat switch fat to ->s_d_op, close exportfs races there 2011-01-12 20:02:43 -05:00
freevxfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
fscache FS-Cache: Fix operation handling 2011-01-14 09:23:36 -08:00
fuse switch fuse 2011-01-12 20:02:44 -05:00
gfs2 mm: prevent concurrent unmap_mapping_range() on the same inode 2011-02-23 19:52:52 -08:00
hfs switch hfs 2011-01-12 20:02:45 -05:00
hfsplus hfsplus: fix up a comparism in hfsplus_file_extend 2011-02-03 16:34:18 -07:00
hostfs switch hostfs 2011-01-12 20:03:42 -05:00
hpfs hpfs_setattr error case avoids unlock_kernel 2011-01-17 05:11:37 -05:00
hppfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hugetlbfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
isofs fix isofs d_op handling 2011-01-12 20:02:43 -05:00
jbd fix comment typos concerning "consistent" 2010-12-10 16:04:28 +01:00
jbd2 jbd2: call __jbd2_log_start_commit with j_state_lock write locked 2011-02-12 08:18:24 -05:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2011-01-17 11:15:30 -08:00
jfs Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
lockd NLM: Fix "kernel BUG at fs/lockd/host.c:417!" or ".../host.c:283!" 2011-01-25 15:24:47 -05:00
logfs Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
minix minixfs: kill dead code 2011-01-12 20:02:44 -05:00
ncpfs move internal-only parts of ncpfs headers to fs/ncpfs 2011-01-12 20:03:43 -05:00
nfs NFS: NFSv4 readdir loses entries 2011-01-28 13:41:35 -05:00
nfs_common NFS: Prevent memory allocation failure in nfsacl_encode() 2011-01-25 15:24:47 -05:00
nfsd nfsd: correctly handle return value from nfsd_map_name_to_* 2011-02-16 18:31:05 -05:00
nilfs2 mm: prevent concurrent unmap_mapping_range() on the same inode 2011-02-23 19:52:52 -08:00
nls
notify Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-01-13 10:05:56 -08:00
ntfs NTFS: Fix invalid pointer dereference in ntfs_mft_record_alloc(). 2011-01-31 12:58:11 +10:00
ocfs2 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 2011-01-21 07:33:37 -08:00
omfs
openpromfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
partitions fs/partitions: Validate map_count in Mac partition tables 2011-02-17 17:50:51 -08:00
proc s390: remove task_show_regs 2011-02-15 07:34:16 -08:00
qnx4 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
quota quota: Fix deadlock during path resolution 2011-01-12 19:14:55 +01:00
ramfs
reiserfs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 2011-01-21 07:33:37 -08:00
romfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
squashfs squashfs: fix use of uninitialised variable in zlib & xz decompressors 2011-01-26 10:50:05 +10:00
sysfs kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
sysv switch sysv 2011-01-12 20:02:44 -05:00
ubifs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
udf Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6 2011-01-11 14:45:52 -08:00
ufs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
xfs xfs: check if device support discard in xfs_ioc_trim() 2011-02-22 15:08:44 -06:00
aio.c aio: check return value of create_workqueue() 2011-01-17 05:12:44 -05:00
anon_inodes.c sanitize vfsmount refcounting changes 2011-01-16 13:47:07 -05:00
attr.c
bad_inode.c fs: provide rcu-walk aware permission i_ops 2011-01-07 17:50:29 +11:00
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c binfmt_elf: cleanups 2011-01-13 08:03:12 -08:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c bio-integrity: mark kintegrityd_wq highpri and CPU intensive 2011-01-03 15:01:48 +01:00
bio.c bio: take care not overflow page count when mapping/copying user data 2010-11-10 14:40:43 +01:00
block_dev.c Merge branch 'for-linus' of git://neil.brown.name/md 2011-02-25 11:13:26 -08:00
buffer.c fs: Use this_cpu_inc_return in buffer.c 2010-12-17 15:18:05 +01:00
char_dev.c Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 2011-01-07 14:39:20 -08:00
compat.c compat: copy missing fields in compat_statfs64 to user 2011-01-17 04:54:38 -05:00
dcache.c fs: fix new dcache.c kernel-doc warnings 2011-01-22 20:32:38 -08:00
dcookies.c
direct-io.c fs/direct-io.c: don't try to allocate more than BIO_MAX_PAGES in a bio 2011-01-20 17:02:05 -08:00
drop_caches.c
eventfd.c Docbook: add fs/eventfd.c and fix typos in it 2011-02-21 15:07:04 -08:00
eventpoll.c epoll: prevent creating circular epoll structures 2011-02-25 15:07:36 -08:00
exec.c vfs: sparse: add __FMODE_EXEC 2011-02-02 16:03:19 -08:00
fcntl.c vfs: sparse: add __FMODE_EXEC 2011-02-02 16:03:19 -08:00
fifo.c
file_table.c CRED: Fix kernel panic upon security_file_alloc() failure. 2011-02-04 10:40:29 -08:00
file.c
filesystems.c fs: rcu-walk for path lookup 2011-01-07 17:50:27 +11:00
fs_struct.c sanitize vfsmount refcounting changes 2011-01-16 13:47:07 -05:00
fs-writeback.c fs/fs-writeback.c: fix sync_inodes_sb() return value kernel-doc 2011-01-13 17:32:48 -08:00
generic_acl.c fs: provide simple rcu-walk generic_check_acl implementation 2011-01-07 17:50:29 +11:00
inode.c Merge branch 'for-linus' of git://neil.brown.name/md 2011-02-25 11:13:26 -08:00
internal.h Fix over-zealous flush_disk when changing device size. 2011-02-24 17:25:47 +11:00
ioctl.c fs: make block fiemap mapping length at least blocksize long 2011-02-02 16:03:20 -08:00
ioprio.c ioprio: grab rcu_read_lock in sys_ioprio_{set,get}() 2010-11-15 10:23:31 +01:00
Kconfig kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
Kconfig.binfmt
libfs.c pass default dentry_operations to mount_pseudo() 2011-01-12 20:03:43 -05:00
locks.c Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linux 2011-01-14 13:17:26 -08:00
Makefile
mbcache.c ext2: Resolve 'dereferencing pointer to incomplete type' when enabling EXT2_XATTR_DEBUG 2011-01-10 19:04:08 +01:00
mpage.c fs/mpage.c: consolidate code 2011-01-13 17:32:32 -08:00
namei.c vfs: fix BUG_ON() in fs/namei.c:1461 2011-02-16 08:56:55 -08:00
namespace.c Unlock vfsmount_lock in do_umount 2011-02-24 02:10:57 -05:00
nfsctl.c
no-block.c
open.c Fix possible filp_cachep memory corruption 2011-02-11 15:53:38 -08:00
pipe.c Fix broken "pipe: use event aware wakeups" optimization 2011-01-20 16:21:59 -08:00
pnode.c fs: scale mntget/mntput 2011-01-07 17:50:33 +11:00
pnode.h
posix_acl.c NFS: Prevent memory allocation failure in nfsacl_encode() 2011-01-25 15:24:47 -05:00
read_write.c fix signedness mess in rw_verify_area() on 64bit architectures 2011-01-12 20:06:58 -05:00
read_write.h
readdir.c
select.c fs/select.c: fix information leak to userspace 2011-01-13 08:03:12 -08:00
seq_file.c
signalfd.c
splice.c Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
stack.c
stat.c Add an AT_NO_AUTOMOUNT flag to suppress terminal automount 2011-01-15 20:07:33 -05:00
statfs.c
super.c vfs: call rcu_barrier after ->kill_sb() 2011-02-11 16:12:19 -08:00
sync.c
timerfd.c
utimes.c
xattr_acl.c
xattr.c