linux/fs
Qu Wenruo 1d8ba9e7e7 btrfs: handle remount to no compress during compression
[BUG]
When running btrfs/071 with inode_need_compress() removed from
compress_file_range(), we got the following crash:

  BUG: kernel NULL pointer dereference, address: 0000000000000018
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  Workqueue: btrfs-delalloc btrfs_work_helper [btrfs]
  RIP: 0010:compress_file_range+0x476/0x7b0 [btrfs]
  Call Trace:
   ? submit_compressed_extents+0x450/0x450 [btrfs]
   async_cow_start+0x16/0x40 [btrfs]
   btrfs_work_helper+0xf2/0x3e0 [btrfs]
   process_one_work+0x278/0x5e0
   worker_thread+0x55/0x400
   ? process_one_work+0x5e0/0x5e0
   kthread+0x168/0x190
   ? kthread_create_worker_on_cpu+0x70/0x70
   ret_from_fork+0x22/0x30
  ---[ end trace 65faf4eae941fa7d ]---

This is already after the patch "btrfs: inode: fix NULL pointer
dereference if inode doesn't need compression."

[CAUSE]
@pages is firstly created by kcalloc() in compress_file_extent():
                pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);

Then passed to btrfs_compress_pages() to be utilized there:

                ret = btrfs_compress_pages(...
                                           pages,
                                           &nr_pages,
                                           ...);

btrfs_compress_pages() will initialize each page as output, in
zlib_compress_pages() we have:

                        pages[nr_pages] = out_page;
                        nr_pages++;

Normally this is completely fine, but there is a special case which
is in btrfs_compress_pages() itself:

        switch (type) {
        default:
                return -E2BIG;
        }

In this case, we didn't modify @pages nor @out_pages, leaving them
untouched, then when we cleanup pages, the we can hit NULL pointer
dereference again:

        if (pages) {
                for (i = 0; i < nr_pages; i++) {
                        WARN_ON(pages[i]->mapping);
                        put_page(pages[i]);
                }
        ...
        }

Since pages[i] are all initialized to zero, and btrfs_compress_pages()
doesn't change them at all, accessing pages[i]->mapping would lead to
NULL pointer dereference.

This is not possible for current kernel, as we check
inode_need_compress() before doing pages allocation.
But if we're going to remove that inode_need_compress() in
compress_file_extent(), then it's going to be a problem.

[FIX]
When btrfs_compress_pages() hits its default case, modify @out_pages to
0 to prevent such problem from happening.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212331
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19 21:32:45 +02:00
..
9p Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-27 08:07:12 -08:00
adfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
affs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
afs afs: Use wait_on_page_writeback_killable 2021-03-23 20:54:37 +00:00
autofs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
befs [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
bfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
btrfs btrfs: handle remount to no compress during compression 2021-04-19 21:32:45 +02:00
cachefiles cachefiles, afs: mm wait fixes 2021-03-24 10:22:00 -07:00
ceph idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
cifs cifs: escape spaces in share names 2021-04-07 21:30:27 -05:00
coda fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
configfs configfs: fix a use-after-free in __configfs_open_file 2021-03-11 12:13:48 +01:00
cramfs cramfs: use %pD instead of messing with file_dentry()->d_name 2021-01-05 23:02:47 -05:00
crypto block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
debugfs Driver core / debugfs update for 5.12-rc1 2021-02-24 10:13:55 -08:00
devpts
dlm fs: dlm: check on existing node address 2020-11-10 12:14:20 -06:00
ecryptfs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
efivarfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
efs [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
erofs Change since last update: 2021-03-13 12:26:22 -08:00
exfat idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
exportfs exportfs: Add a function to return the raw output from fh_to_dentry() 2020-12-09 09:39:38 -05:00
ext2 fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
ext4 Miscellaneous ext4 bug fixes for v5.12. 2021-03-21 14:06:10 -07:00
f2fs block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
fat idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
freevxfs
fscache
fuse fuse: 32-bit user space ioctl compat for fuse device 2021-03-16 15:20:16 +01:00
gfs2 Two more gfs2 fixes 2021-04-03 12:15:01 -07:00
hfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
hfsplus idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
hostfs hostfs: fix memory handling in follow_link() 2021-03-25 18:57:42 -04:00
hpfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
hugetlbfs hugetlbfs: remove unneeded return value of hugetlb_vmtruncate() 2021-02-24 13:38:35 -08:00
iomap Merge branch 'iomap-5.12-fixes' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux 2021-03-18 10:37:30 -07:00
isofs isofs: handle large user and group ID 2021-02-03 19:05:52 +01:00
jbd2 block: use an on-stack bio in blkdev_issue_flush 2021-01-27 09:51:48 -07:00
jffs2 idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
jfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-27 08:07:12 -08:00
kernfs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
lockd SUNRPC: Make trace_svc_process() display the RPC procedure symbolically 2021-01-25 09:36:23 -05:00
minix fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
nfs nfs: we don't support removing system.nfs4_acl 2021-03-11 13:17:42 -05:00
nfs_common NFSv4_2: SSC helper should use its own config. 2021-01-28 10:55:37 -05:00
nfsd NFSD: fix error handling in NFSv4.0 callbacks 2021-03-11 10:58:49 -05:00
nilfs2 block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
nls
notify idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
ntfs ntfs: check for valid standard information attribute 2021-02-24 13:38:26 -08:00
ocfs2 ocfs2: fix deadlock between setattr and dio_end_io_write 2021-04-09 14:54:23 -07:00
omfs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
openpromfs
orangefs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
overlayfs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
proc mm: use is_cow_mapping() across tree where proper 2021-03-13 11:27:30 -08:00
pstore pstore fixes for v5.12-rc2 2021-03-05 17:21:25 -08:00
qnx4 [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
qnx6 [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
quota quota: Fix memory leak when handling corrupted quota file 2021-01-05 14:42:18 +01:00
ramfs ramfs: support O_TMPFILE 2021-02-24 13:38:26 -08:00
reiserfs reiserfs: update reiserfs_xattrs_initialized() condition 2021-03-30 14:27:32 -07:00
romfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
squashfs squashfs: fix xattr id and id lookup sanity checks 2021-03-25 09:22:55 -07:00
sysfs sysfs: Support zapping of binary attr mmaps 2021-01-12 14:26:31 +01:00
sysv fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
tracefs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
ubifs idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
udf idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
ufs fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
unicode unicode: Add utf8_casefold_hash 2020-09-10 14:03:31 -07:00
vboxsf fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
verity idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
xfs xfs: also reject BULKSTAT_SINGLE in a mount user namespace 2021-03-15 08:50:41 -07:00
zonefs zonefs: fix to update .i_wr_refcnt correctly in zonefs_open_zone() 2021-03-17 08:56:50 +09:00
aio.c Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
anon_inodes.c fs: anon_inodes: rephrase to appropriate kernel-doc 2021-01-15 12:17:25 -05:00
attr.c ima: handle idmapped mounts 2021-01-24 14:27:20 +01:00
bad_inode.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
binfmt_aout.c
binfmt_elf_fdpic.c Merge branch 'parisc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2021-02-21 13:20:41 -08:00
binfmt_elf.c Merge branch 'parisc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2021-02-21 13:20:41 -08:00
binfmt_em86.c
binfmt_flat.c binfmt_flat: revert "binfmt_flat: don't offset the data start" 2020-08-24 08:49:13 +10:00
binfmt_misc.c binfmt_misc: fix possible deadlock in bm_register_write 2021-03-13 11:27:30 -08:00
binfmt_script.c
block_dev.c block: don't ignore REQ_NOWAIT for direct IO 2021-04-02 08:34:30 -06:00
buffer.c fs: buffer: use raw page_memcg() on locked page 2021-02-24 13:38:30 -08:00
char_dev.c
compat_binfmt_elf.c get rid of COMPAT_ELF_EXEC_PAGESIZE 2021-01-06 08:42:51 -05:00
coredump.c fs/coredump: use kmap_local_page() 2021-02-26 09:41:05 -08:00
d_path.c fs: fix NULL dereference due to data race in prepend_path() 2020-10-14 14:54:45 -07:00
dax.c mm: provide a saner PTE walking API for modules 2021-02-09 07:05:44 -05:00
dcache.c fs: delete repeated words in comments 2021-02-24 13:38:26 -08:00
direct-io.c fs: direct-io: fix missing sdio->boundary 2021-04-09 14:54:23 -07:00
drop_caches.c
eventfd.c eventfd: Export eventfd_ctx_do_read() 2020-11-15 09:49:10 -05:00
eventpoll.c kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE 2021-02-16 09:59:41 +01:00
exec.c fs: delete repeated words in comments 2021-02-24 13:38:26 -08:00
fcntl.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
fhandle.c fs: delete repeated words in comments 2021-02-24 13:38:26 -08:00
file_table.c epoll: take epitem list out of struct file 2020-10-25 20:02:08 -04:00
file.c file: fix close_range() for unshare+cloexec 2021-04-02 14:11:10 +02:00
filesystems.c
fs_context.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
fs_parser.c fs_parse: mark fs_param_bad_value() as static 2020-10-13 18:38:27 -07:00
fs_pin.c
fs_struct.c vfs: Use sequence counter with associated spinlock 2020-07-29 16:14:27 +02:00
fs_types.c
fs-writeback.c fs: improve comments for writeback_single_inode() 2021-01-13 17:26:50 +01:00
fsopen.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
init.c init: handle idmapped mounts 2021-01-24 14:27:19 +01:00
inode.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-27 08:07:12 -08:00
internal.h idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
io_uring.c io_uring: fix early sqd_list removal sqpoll hangs 2021-04-14 13:07:27 -06:00
io-wq.c io-wq: cancel unbounded works on io-wq destroy 2021-04-08 13:33:17 -06:00
io-wq.h io_uring: remove structures from include/linux/io_uring.h 2021-03-18 09:44:35 -06:00
ioctl.c fs: remove ksys_ioctl 2020-07-31 08:16:01 +02:00
Kconfig s390,alpha: make TMPFS_INODE64 available again 2021-03-08 10:46:30 +01:00
Kconfig.binfmt Merge branch 'work.elf-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-21 09:29:23 -08:00
kernel_read_file.c fs/kernel_file_read: Add "offset" arg for partial reads 2020-10-05 13:37:04 +02:00
libfs.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
locks.c Revert "nfsd4: a client's own opens needn't prevent delegations" 2021-03-09 10:37:34 -05:00
Makefile fs: Remove dcookies support 2021-01-29 10:06:46 +05:30
mbcache.c
mount.h mount: make {lock,unlock}_mount_hash() static 2021-01-24 14:29:34 +01:00
mpage.c block: rename BIO_MAX_PAGES to BIO_MAX_VECS 2021-03-11 07:47:48 -07:00
namei.c LOOKUP_MOUNTPOINT: we are cleaning "jumped" flag too late 2021-04-06 20:33:00 -04:00
namespace.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-27 08:07:12 -08:00
no-block.c
nsfs.c
open.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
pipe.c fs: delete repeated words in comments 2021-02-24 13:38:26 -08:00
pnode.c
pnode.h mount: fix mounting of detached mounts onto targets that reside on shared mounts 2021-03-08 15:18:43 +01:00
posix_acl.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
proc_namespace.c fs: introduce MOUNT_ATTR_IDMAP 2021-01-24 14:43:45 +01:00
read_write.c teach sendfile(2) to handle send-to-pipe directly 2021-01-25 23:29:36 -05:00
readdir.c readdir: make sure to verify directory entry for legacy interfaces too 2021-04-17 11:39:49 -07:00
remap_range.c ioctl: handle idmapped mounts 2021-01-24 14:27:19 +01:00
select.c kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data() 2021-03-16 22:13:10 +01:00
seq_file.c fs: fix kernel-doc markups 2021-01-21 14:06:00 -07:00
signalfd.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
splice.c for-5.12/block-2021-02-17 2021-02-21 11:02:48 -08:00
stack.c
stat.c fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
statfs.c s390,alpha: switch to 64-bit ino_t 2021-02-13 17:17:53 +01:00
super.c It has been a relatively quiet cycle in docsland. 2021-02-22 10:57:46 -08:00
sync.c
timerfd.c
userfaultfd.c userfaultfd: use secure anon inodes for userfaultfd 2021-01-14 17:40:57 -05:00
utimes.c utimes: handle idmapped mounts 2021-01-24 14:27:18 +01:00
xattr.c namei: handle idmapped mounts in may_*() helpers 2021-01-24 14:27:17 +01:00