linux/fs
Christophe Leroy 3acd48507d btrfs: fix allocation of free space cache v1 bitmap pages
Various notifications of type "BUG kmalloc-4096 () : Redzone
overwritten" have been observed recently in various parts of the kernel.
After some time, it has been made a relation with the use of BTRFS
filesystem and with SLUB_DEBUG turned on.

[   22.809700] BUG kmalloc-4096 (Tainted: G        W        ): Redzone overwritten

[   22.810286] INFO: 0xbe1a5921-0xfbfc06cd. First byte 0x0 instead of 0xcc
[   22.810866] INFO: Allocated in __load_free_space_cache+0x588/0x780 [btrfs] age=22 cpu=0 pid=224
[   22.811193] 	__slab_alloc.constprop.26+0x44/0x70
[   22.811345] 	kmem_cache_alloc_trace+0xf0/0x2ec
[   22.811588] 	__load_free_space_cache+0x588/0x780 [btrfs]
[   22.811848] 	load_free_space_cache+0xf4/0x1b0 [btrfs]
[   22.812090] 	cache_block_group+0x1d0/0x3d0 [btrfs]
[   22.812321] 	find_free_extent+0x680/0x12a4 [btrfs]
[   22.812549] 	btrfs_reserve_extent+0xec/0x220 [btrfs]
[   22.812785] 	btrfs_alloc_tree_block+0x178/0x5f4 [btrfs]
[   22.813032] 	__btrfs_cow_block+0x150/0x5d4 [btrfs]
[   22.813262] 	btrfs_cow_block+0x194/0x298 [btrfs]
[   22.813484] 	commit_cowonly_roots+0x44/0x294 [btrfs]
[   22.813718] 	btrfs_commit_transaction+0x63c/0xc0c [btrfs]
[   22.813973] 	close_ctree+0xf8/0x2a4 [btrfs]
[   22.814107] 	generic_shutdown_super+0x80/0x110
[   22.814250] 	kill_anon_super+0x18/0x30
[   22.814437] 	btrfs_kill_super+0x18/0x90 [btrfs]
[   22.814590] INFO: Freed in proc_cgroup_show+0xc0/0x248 age=41 cpu=0 pid=83
[   22.814841] 	proc_cgroup_show+0xc0/0x248
[   22.814967] 	proc_single_show+0x54/0x98
[   22.815086] 	seq_read+0x278/0x45c
[   22.815190] 	__vfs_read+0x28/0x17c
[   22.815289] 	vfs_read+0xa8/0x14c
[   22.815381] 	ksys_read+0x50/0x94
[   22.815475] 	ret_from_syscall+0x0/0x38

Commit 69d2480456 ("btrfs: use copy_page for copying pages instead of
memcpy") changed the way bitmap blocks are copied. But allthough bitmaps
have the size of a page, they were allocated with kzalloc().

Most of the time, kzalloc() allocates aligned blocks of memory, so
copy_page() can be used. But when some debug options like SLAB_DEBUG are
activated, kzalloc() may return unaligned pointer.

On powerpc, memcpy(), copy_page() and other copying functions use
'dcbz' instruction which provides an entire zeroed cacheline to avoid
memory read when the intention is to overwrite a full line. Functions
like memcpy() are writen to care about partial cachelines at the start
and end of the destination, but copy_page() assumes it gets pages. As
pages are naturally cache aligned, copy_page() doesn't care about
partial lines. This means that when copy_page() is called with a
misaligned pointer, a few leading bytes are zeroed.

To fix it, allocate bitmaps through kmem_cache instead of using kzalloc()
The cache pool is created with PAGE_SIZE alignment constraint.

Reported-by: Erhard F. <erhard_f@mailbox.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204371
Fixes: 69d2480456 ("btrfs: use copy_page for copying pages instead of memcpy")
Cc: stable@vger.kernel.org # 4.19+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: David Sterba <dsterba@suse.com>
[ rename to btrfs_free_space_bitmap ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:14 +02:00
..
9p 9p: pass the correct prototype to read_cache_page 2019-07-12 11:05:43 -07:00
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 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
afs afs: use correct afs_call_type in yfs_fs_store_opaque_acl2 2019-08-22 13:33:27 +01:00
autofs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 83 2019-05-24 17:37:52 +02:00
befs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
bfs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
btrfs btrfs: fix allocation of free space cache v1 bitmap pages 2019-09-09 14:59:14 +02:00
cachefiles treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
ceph ceph: don't try fill file_lock on unsuccessful GETFILELOCK reply 2019-08-22 10:47:41 +02:00
cifs cifs: update internal module number 2019-08-27 17:29:56 -05:00
coda coda: add hinting support for partial file caching 2019-07-16 19:23:23 -07:00
configfs configfs: provide exclusion between IO and removals 2019-09-04 22:33:51 +02:00
cramfs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
crypto 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
debugfs Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
devpts devpts: call fsnotify_unlink() hook 2019-06-20 14:46:34 +02:00
dlm dlm for 5.3 2019-07-12 17:37:53 -07:00
ecryptfs - Fix error handling when ecryptfs_read_lower() encounters an error 2019-07-14 19:29:04 -07:00
efivarfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
efs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
exportfs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ext2 New for 5.3: 2019-07-12 16:54:37 -07:00
ext4 - virtio_pmem: The new virtio_pmem facility introduces a paravirtualized 2019-07-18 10:52:08 -07:00
f2fs f2fs-for-5.4-rc3 2019-07-30 13:15:39 -07:00
fat treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
freevxfs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
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 Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
gfs2 gfs2: gfs2_walk_metadata fix 2019-08-09 16:56:12 +01:00
hfs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
hfsplus fs/hfsplus/xattr.c: replace strncpy with memcpy 2019-07-16 19:23:23 -07:00
hostfs This pull request contains the following changes for UML: 2019-05-12 17:52:13 -04:00
hpfs treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
hugetlbfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
iomap iomap: fix Invalid License ID 2019-07-25 11:05:11 +02:00
isofs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 142 2019-05-30 11:25:17 -07:00
jbd2 jbd2: drop declaration of journal_sync_buffer() 2019-06-20 17:32:21 -04:00
jffs2 jffs2: pass the correct prototype to read_cache_page 2019-07-12 11:05:43 -07:00
jfs vfs: create a generic checking and prep function for FS_IOC_SETFLAGS 2019-07-01 08:25:34 -07:00
kernfs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
lockd lockd: Make two symbols static 2019-07-03 17:52:09 -04:00
minix treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
nfs NFS: Fix inode fileid checks in attribute revalidation code 2019-09-02 13:10:19 -04:00
nfs_common treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
nfsd nfsd4: Fix kernel crash when reading proc file reply_cache_stats 2019-08-16 13:36:55 -04:00
nilfs2 vfs: create a generic checking and prep function for FS_IOC_SETFLAGS 2019-07-01 08:25:34 -07:00
nls treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
notify proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
ntfs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 97 2019-05-24 17:37:53 +02:00
ocfs2 ocfs2: remove set but not used variable 'last_hash' 2019-08-03 07:02:00 -07:00
omfs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 209 2019-05-30 11:29:53 -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: This simple pull request is just a fix for an 2019-07-16 15:15:29 -07:00
overlayfs SPDX update for 5.2-rc6 2019-06-21 09:58:42 -07:00
proc Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
pstore pstore: Fix double-free in pstore_mkfile() failure path 2019-07-08 21:04:42 -07:00
qnx4 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
qnx6 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
quota \n 2019-07-10 20:27:07 -07:00
ramfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
reiserfs fs/reiserfs/journal.c: change return type of dirty_one_transaction 2019-07-16 19:23:24 -07:00
romfs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
squashfs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
sysfs Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
sysv treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
tracefs \n 2019-07-10 20:09:17 -07:00
ubifs ubifs: Limit the number of pages in shrink_liability 2019-08-22 17:25:33 +02:00
udf \n 2019-07-10 20:27:07 -07:00
ufs fs/ufs/super.c: remove set but not used variable 'usb3' 2019-07-16 19:23:23 -07:00
unicode Many bug fixes and cleanups, and an optimization for case-insensitive 2019-07-10 21:06:01 -07:00
xfs xfs: fix missing ILOCK unlock when xfs_setattr_nonsize fails due to EDQUOT 2019-08-22 20:55:54 -07:00
aio.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
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
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: delete stale comment 2019-07-16 19:23:22 -07:00
binfmt_em86.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
binfmt_flat.c fs/binfmt_flat.c: remove set but not used variable 'inode' 2019-07-16 19:23:22 -07:00
binfmt_misc.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
binfmt_script.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
block_dev.c block: remove REQ_NOWAIT_INLINE 2019-08-15 11:09:16 -06:00
buffer.c for-linus-20190715 2019-07-15 21:20:52 -07:00
char_dev.c chardev: set variable ret to -EBUSY before checking minor range overlap 2019-05-24 20:50:36 +02:00
compat_binfmt_elf.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
compat_ioctl.c compat_ioctl: pppoe: fix PPPOEIOCSFWD handling 2019-07-30 14:42:13 -07:00
compat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
coredump.c coredump: split pipe command whitespace before expanding template 2019-08-03 07:02:01 -07:00
d_path.c unexport simple_dname() 2019-05-21 08:23:41 +01:00
dax.c dax: dax_layout_busy_page() should not unmap cow pages 2019-08-05 14:59:05 -07:00
dcache.c Merge branch 'work.dcache2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-20 09:15:51 -07:00
dcookies.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
direct-io.c direct-io: use bio_release_pages in dio_bio_complete 2019-06-29 09:47:31 -06:00
drop_caches.c
eventfd.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
eventpoll.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
exec.c sched/fair: Don't free p->numa_faults with concurrent readers 2019-07-25 15:37:04 +02:00
fcntl.c fs: mark expected switch fall-throughs 2019-04-08 18:21:02 -05:00
fhandle.c
file_table.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
file.c io_uring-2019-03-06 2019-03-08 14:48:40 -08:00
filesystems.c vfs: Implement a filesystem superblock creation/configuration context 2019-02-28 03:29:26 -05:00
fs_context.c move mount_capable() calls to vfs_get_tree() 2019-05-25 18:00:01 -04:00
fs_parser.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
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 blkcg, writeback: Add wbc->no_cgroup_owner 2019-07-10 09:00:57 -06:00
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 New for 5.3: 2019-07-12 16:54:37 -07:00
internal.h Merge branch 'work.dcache2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-20 09:15:51 -07:00
io_uring.c io_uring: add need_resched() check in inner poll loop 2019-08-22 15:32:28 -06:00
ioctl.c
Kconfig fs: VALIDATE_FS_PARSER should default to n 2019-07-05 11:22:11 -04:00
Kconfig.binfmt binfmt_flat: make support for old format binaries optional 2019-06-24 09:16:47 +10:00
libfs.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
locks.c Highlights: 2019-07-10 21:22:43 -07:00
Makefile iomap: move the main iteration code into a separate file 2019-07-17 07:20:43 -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 blkcg, writeback: Rename wbc_account_io() to wbc_account_cgroup_owner() 2019-07-10 09:00:57 -06:00
namei.c fsnotify: add empty fsnotify_{unlink,rmdir}() hooks 2019-06-20 14:44:55 +02:00
namespace.c fix the struct mount leak in umount_tree() 2019-07-26 07:59:06 -04:00
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 access: avoid the RCU grace period for the temporary subjective credentials 2019-07-24 10:12:09 -07:00
pipe.c vfs: Convert pipe to use the new mount API 2019-05-25 18:00:07 -04:00
pnode.c fs/namespace: fix unprivileged mount propagation 2019-06-17 17:36:09 -04:00
pnode.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 209 2019-05-30 11:29:53 -07:00
posix_acl.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
proc_namespace.c
read_write.c vfs: fix page locking deadlocks when deduping files 2019-08-16 18:43:24 -07:00
readdir.c
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: mark expected switch fall-throughs 2019-04-08 18:21:02 -05:00
splice.c uio: make import_iovec()/compat_import_iovec() return bytes on success 2019-05-31 15:30:03 -06:00
stack.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
stat.c
statfs.c
super.c Unbreak mount_capable() 2019-07-31 12:22:32 -04:00
sync.c fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writeback 2019-05-14 09:47:50 -07:00
timerfd.c
userfaultfd.c userfaultfd_release: always remove uffd flags and clear vm_userfaultfd_ctx 2019-08-24 19:48:42 -07:00
utimes.c
xattr.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00