linux_dsm_epyc7002/fs
David Sterba bc4ef7592f btrfs: properly set the termination value of ctx->pos in readdir
The value of ctx->pos in the last readdir call is supposed to be set to
INT_MAX due to 32bit compatibility, unless 'pos' is intentially set to a
larger value, then it's LLONG_MAX.

There's a report from PaX SIZE_OVERFLOW plugin that "ctx->pos++"
overflows (https://forums.grsecurity.net/viewtopic.php?f=1&t=4284), on a
64bit arch, where the value is 0x7fffffffffffffff ie. LLONG_MAX before
the increment.

We can get to that situation like that:

* emit all regular readdir entries
* still in the same call to readdir, bump the last pos to INT_MAX
* next call to readdir will not emit any entries, but will reach the
  bump code again, finds pos to be INT_MAX and sets it to LLONG_MAX

Normally this is not a problem, but if we call readdir again, we'll find
'pos' set to LLONG_MAX and the unconditional increment will overflow.

The report from Victor at
(http://thread.gmane.org/gmane.comp.file-systems.btrfs/49500) with debugging
print shows that pattern:

 Overflow: e
 Overflow: 7fffffff
 Overflow: 7fffffffffffffff
 PAX: size overflow detected in function btrfs_real_readdir
   fs/btrfs/inode.c:5760 cicus.935_282 max, count: 9, decl: pos; num: 0;
   context: dir_context;
 CPU: 0 PID: 2630 Comm: polkitd Not tainted 4.2.3-grsec #1
 Hardware name: Gigabyte Technology Co., Ltd. H81ND2H/H81ND2H, BIOS F3 08/11/2015
  ffffffff81901608 0000000000000000 ffffffff819015e6 ffffc90004973d48
  ffffffff81742f0f 0000000000000007 ffffffff81901608 ffffc90004973d78
  ffffffff811cb706 0000000000000000 ffff8800d47359e0 ffffc90004973ed8
 Call Trace:
  [<ffffffff81742f0f>] dump_stack+0x4c/0x7f
  [<ffffffff811cb706>] report_size_overflow+0x36/0x40
  [<ffffffff812ef0bc>] btrfs_real_readdir+0x69c/0x6d0
  [<ffffffff811dafc8>] iterate_dir+0xa8/0x150
  [<ffffffff811e6d8d>] ? __fget_light+0x2d/0x70
  [<ffffffff811dba3a>] SyS_getdents+0xba/0x1c0
 Overflow: 1a
  [<ffffffff811db070>] ? iterate_dir+0x150/0x150
  [<ffffffff81749b69>] entry_SYSCALL_64_fastpath+0x12/0x83

The jump from 7fffffff to 7fffffffffffffff happens when new dir entries
are not yet synced and are processed from the delayed list. Then the code
could go to the bump section again even though it might not emit any new
dir entries from the delayed list.

The fix avoids entering the "bump" section again once we've finished
emitting the entries, both for synced and delayed entries.

References: https://forums.grsecurity.net/viewtopic.php?f=1&t=4284
Reported-by: Victor <services@swwu.com>
CC: stable@vger.kernel.org
Signed-off-by: David Sterba <dsterba@suse.com>
Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-02-11 07:01:59 -08:00
..
9p 9p: ->evict_inode() should kick out ->i_data, not ->i_mapping 2015-12-08 14:51:16 -05:00
adfs fs/adfs: remove unneeded cast 2015-06-30 19:44:57 -07:00
affs fs/affs: make root lookup from blkdev logical size 2015-09-10 13:29:01 -07:00
afs net: Add a struct net parameter to sock_create_kern 2015-05-11 10:50:17 -04:00
autofs4 make simple_positive() public 2015-06-23 18:02:01 -04:00
befs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-07-04 19:36:06 -07:00
bfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
btrfs btrfs: properly set the termination value of ctx->pos in readdir 2016-02-11 07:01:59 -08:00
cachefiles FS-Cache: Add missing initialization of ret in cachefiles_write_page() 2015-11-16 20:38:43 -05:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2015-11-13 09:24:40 -08:00
cifs sched/wait: Fix the signal handling fix 2015-12-13 14:30:59 -08:00
coda fs/coda: fix readlink buffer overflow 2015-09-10 13:29:01 -07:00
configfs configfs: allow dynamic group creation 2015-11-20 16:17:32 -08:00
cramfs
debugfs debugfs: fix refcount imbalance in start_creating 2015-11-11 02:04:44 -05:00
devpts devpts: if initialization failed, don't crash when opening /dev/ptmx 2015-06-30 19:44:58 -07:00
dlm net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA 2015-12-01 15:45:05 -05:00
ecryptfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2015-11-07 13:05:44 -08:00
efivarfs Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-05-06 10:57:37 -07:00
efs fs/efs: femove unneeded cast 2015-06-25 17:00:42 -07:00
exofs osd fs: __r4w_get_page rely on PageUptodate for uptodate 2015-12-12 10:15:34 -08:00
exportfs VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
ext2 ext2, ext4: warn when mounting with dax enabled 2015-11-16 09:43:54 -08:00
ext4 Ext4 bug fixes for v4.4, including fixes for post-2038 time encodings, 2015-12-07 10:25:00 -08:00
f2fs Merge branch 'for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-11-13 18:02:30 -08:00
fat fat: fix fake_offset handling on error path 2015-11-20 16:17:32 -08:00
freevxfs freevxfs: Grammar s/an negative/a negative/ 2015-08-07 13:59:24 +02:00
fscache FS-Cache: Handle a write to the page immediately beyond the EOF marker 2015-11-11 02:11:02 -05:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse 2015-12-11 10:56:41 -08:00
gfs2 Merge branch 'for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-11-13 18:02:30 -08:00
hfs hfs: fix B-tree corruption after insertion at position 0 2015-09-10 13:29:01 -07:00
hfsplus xattr handlers: Pass handler to operations instead of flags 2015-11-13 20:34:32 -05:00
hostfs fs: create and use seq_show_option for escaping 2015-09-04 16:54:41 -07:00
hpfs fs/hpfs/namei.c: remove unnecessary new_valid_dev() check 2015-11-09 15:11:24 -08:00
hugetlbfs mm/hugetlbfs: fix bugs in fallocate hole punch of areas with holes 2015-11-20 16:17:32 -08:00
isofs VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
jbd2 Ext4 bug fixes for v4.4, including fixes for post-2038 time encodings, 2015-12-07 10:25:00 -08:00
jffs2 xattr handlers: Pass handler to operations instead of flags 2015-11-13 20:34:32 -05:00
jfs fs/jfs: remove unnecessary new_valid_dev() checks 2015-11-09 15:11:24 -08:00
kernfs kernfs: implement kernfs_path_len() 2015-08-18 15:49:15 -07:00
lockd Mainly smaller bugfixes and cleanup. We're still finding some bugs from 2015-11-11 20:11:28 -08:00
logfs mm, fs: introduce mapping_gfp_constraint() 2015-11-06 17:50:42 -08:00
minix Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-07-04 19:36:06 -07:00
ncpfs ncpfs: don't allow negative timeouts 2015-11-20 16:17:32 -08:00
nfs sched/wait: Fix the signal handling fix 2015-12-13 14:30:59 -08:00
nfs_common lockd: NLM grace period shouldn't block NFSv4 opens 2015-08-13 10:22:06 -04:00
nfsd nfsd: fix race with open / open upgrade stateids 2015-11-10 09:29:45 -05:00
nilfs2 Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-11-11 09:45:24 -08:00
nls
notify inotify: actually check for invalid bits in sys_inotify_add_watch() 2015-11-05 19:34:48 -08:00
ntfs mm, fs: introduce mapping_gfp_constraint() 2015-11-06 17:50:42 -08:00
ocfs2 ocfs2: fix SGID not inherited issue 2015-12-12 10:15:34 -08:00
omfs omfs: fix potential integer overflow in allocator 2015-05-28 18:25:19 -07:00
openpromfs
overlayfs ovl: get rid of the dead code left from broken (and disabled) optimizations 2015-12-06 12:31:07 -05:00
proc proc: fix -ESRCH error when writing to /proc/$pid/coredump_filter 2015-12-18 14:25:40 -08:00
pstore pstore: fix code comment to match code 2015-11-02 13:41:52 -08:00
qnx4
qnx6 pagemap.h: move dir_pages() over there 2015-06-23 18:02:00 -04:00
quota Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-09-05 20:34:28 -07:00
ramfs mm, fs: obey gfp_mapping for add_to_page_cache() 2015-10-16 11:42:28 -07:00
reiserfs Merge branch 'for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-11-13 18:02:30 -08:00
romfs make new_sync_{read,write}() static 2015-04-11 22:29:40 -04:00
squashfs squashfs: xattr simplifications 2015-11-13 20:34:33 -05:00
sysfs platform/chrome: Branch for v4.4 2015-11-13 21:53:18 -08:00
sysv fix sysvfs symlinks 2015-11-23 21:11:08 -05:00
tracefs tracefs: Fix refcount imbalance in start_creating() 2015-11-04 22:13:45 -05:00
ubifs Merge branch 'for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-11-13 18:02:30 -08:00
udf udf: Don't modify filesystem for read-only mounts 2015-08-20 14:58:35 +02:00
ufs fix ufs write vs readpage race when writing into a hole 2015-09-09 10:43:12 -07:00
xfs Merge branch 'for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-11-13 18:02:30 -08:00
aio.c mm: move ->mremap() from file_operations to vm_operations_struct 2015-09-04 16:54:41 -07:00
anon_inodes.c
attr.c
bad_inode.c don't bother with most of the bad_file_ops methods 2015-02-20 04:03:58 -05:00
binfmt_aout.c
binfmt_elf_fdpic.c libnvdimm for 4.4: 2015-11-10 12:07:22 -08:00
binfmt_elf.c Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-11-11 09:45:24 -08:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
binfmt_script.c
block_dev.c block: detach bdev inode from its wb in __blkdev_put() 2015-12-04 11:02:17 -07:00
buffer.c vfs: remove unused wrapper block_page_mkwrite() 2015-11-11 02:19:33 -05:00
char_dev.c fs/char_dev.c: fix incorrect documentation for unregister_chrdev_region 2015-08-05 13:49:35 -07:00
compat_binfmt_elf.c
compat_ioctl.c i2c-dev: Fix typo in ioctl name reference 2015-10-23 23:26:43 +02:00
compat.c
coredump.c coredump: change zap_threads() and zap_process() to use for_each_thread() 2015-11-06 17:50:42 -08:00
dax.c dax: disable pmd mappings 2015-11-16 23:54:45 -08:00
dcache.c dcache: Reduce the scope of i_lock in d_splice_alias 2015-08-21 02:34:37 -04:00
dcookies.c
direct-io.c fix the regression from "direct-io: Fix negative return from dio read beyond eof" 2015-12-08 15:02:42 -05:00
drop_caches.c inode: convert inode_sb_list_lock to per-sb 2015-08-17 18:39:46 -04:00
eventfd.c eventfd: don't take the spinlock in eventfd_poll 2015-02-17 14:34:52 -08:00
eventpoll.c
exec.c vfs: Commit to never having exectuables on proc and sysfs. 2015-07-10 10:39:25 -05:00
fcntl.c
fhandle.c vfs: read file_handle only once in handle_to_path 2015-06-02 10:29:07 -07:00
file_table.c fs, file table: reinit files_stat.max_files after deferred memory initialisation 2015-08-07 04:39:40 +03:00
file.c vfs: clear remainder of 'full_fds_bits' in dup_fd() 2015-11-05 23:05:32 -08:00
filesystems.c
fs_pin.c fs_pin: Allow for the possibility that m_list or s_list go unused. 2015-04-09 11:39:55 -05:00
fs_struct.c
fs-writeback.c fs: fix writeback.c kernel-doc warnings 2015-11-11 02:18:27 -05:00
inode.c fs: fix inode.c kernel-doc warning 2015-11-11 02:18:27 -05:00
internal.h inode: rename i_wb_list to i_io_list 2015-08-17 23:38:10 -04:00
ioctl.c
Kconfig dax: disable pmd mappings 2015-11-16 23:54:45 -08:00
Kconfig.binfmt mm: split ET_DYN ASLR from mmap ASLR 2015-04-14 16:49:05 -07:00
libfs.c fs: Set the size of empty dirs to 0. 2015-08-12 15:28:45 -05:00
locks.c locks: cleanup posix_lock_inode_wait and flock_lock_inode_wait 2015-10-22 14:57:42 -04:00
Makefile ext4: promote ext4 over ext2 in the default probe order 2015-10-15 10:33:21 -04:00
mbcache.c
mount.h fs: use seq_open_private() for proc_mounts 2015-06-30 19:44:56 -07:00
mpage.c mm, fs: introduce mapping_gfp_constraint() 2015-11-06 17:50:42 -08:00
namei.c Don't reset ->total_link_count on nested calls of vfs_path_lookup() 2015-12-06 12:33:02 -05:00
namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2015-09-01 16:13:25 -07:00
no-block.c
nsfs.c fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void 2015-09-11 15:21:34 -07:00
open.c vfs: Commit to never having exectuables on proc and sysfs. 2015-07-10 10:39:25 -05:00
pipe.c fs/pipe.c: return error code rather than 0 in pipe_write() 2015-11-11 02:18:26 -05:00
pnode.c mnt: Don't propagate unmounts to locked mounts 2015-04-02 20:34:20 -05:00
pnode.h mnt: Clarify and correct the disconnect logic in umount_tree 2015-07-22 20:33:27 -05:00
posix_acl.c xattr handlers: Pass handler to operations instead of flags 2015-11-13 20:34:32 -05:00
proc_namespace.c fs: use seq_open_private() for proc_mounts 2015-06-30 19:44:56 -07:00
read_write.c new_sync_write(): discard ->ki_pos unless the return value is positive 2015-04-11 22:29:46 -04:00
readdir.c
select.c locking/arch: Rename set_mb() to smp_store_mb() 2015-05-19 08:32:00 +02:00
seq_file.c fs, seqfile: always allow oom killer 2015-11-06 17:50:42 -08:00
signalfd.c signalfd: fix information leak in signalfd_copyinfo 2015-08-07 04:39:40 +03:00
splice.c vfs: Avoid softlockups with sendfile(2) 2015-11-23 21:15:30 -05:00
stack.c
stat.c fs/stat.c: remove unnecessary new_valid_dev() check 2015-11-09 15:11:24 -08:00
statfs.c
super.c Merge branch 'superblock-scaling' of git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-next into for-next 2015-08-21 02:31:20 -04:00
sync.c fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE writeback 2015-11-06 17:50:42 -08:00
timerfd.c
userfaultfd.c userfaultfd: revert "userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_key" 2015-09-22 15:09:53 -07:00
utimes.c
xattr.c 9p: xattr simplifications 2015-11-13 20:34:33 -05:00