linux_dsm_epyc7002/fs/btrfs
Filipe Manana 580c079b57 btrfs: fix double free on ulist after backref resolution failure
At btrfs_find_all_roots_safe() we allocate a ulist and set the **roots
argument to point to it. However if later we fail due to an error returned
by find_parent_nodes(), we free that ulist but leave a dangling pointer in
the **roots argument. Upon receiving the error, a caller of this function
can attempt to free the same ulist again, resulting in an invalid memory
access.

One such scenario is during qgroup accounting:

btrfs_qgroup_account_extents()

 --> calls btrfs_find_all_roots() passes &new_roots (a stack allocated
     pointer) to btrfs_find_all_roots()

   --> btrfs_find_all_roots() just calls btrfs_find_all_roots_safe()
       passing &new_roots to it

     --> allocates ulist and assigns its address to **roots (which
         points to new_roots from btrfs_qgroup_account_extents())

     --> find_parent_nodes() returns an error, so we free the ulist
         and leave **roots pointing to it after returning

 --> btrfs_qgroup_account_extents() sees btrfs_find_all_roots() returned
     an error and jumps to the label 'cleanup', which just tries to
     free again the same ulist

Stack trace example:

 ------------[ cut here ]------------
 BTRFS: tree first key check failed
 WARNING: CPU: 1 PID: 1763215 at fs/btrfs/disk-io.c:422 btrfs_verify_level_key+0xe0/0x180 [btrfs]
 Modules linked in: dm_snapshot dm_thin_pool (...)
 CPU: 1 PID: 1763215 Comm: fsstress Tainted: G        W         5.8.0-rc3-btrfs-next-64 #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:btrfs_verify_level_key+0xe0/0x180 [btrfs]
 Code: 28 5b 5d (...)
 RSP: 0018:ffffb89b473779a0 EFLAGS: 00010286
 RAX: 0000000000000000 RBX: ffff90397759bf08 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000000027 RDI: 00000000ffffffff
 RBP: ffff9039a419c000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffffb89b43301000 R12: 000000000000005e
 R13: ffffb89b47377a2e R14: ffffb89b473779af R15: 0000000000000000
 FS:  00007fc47e1e1000(0000) GS:ffff9039ac200000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fc47e1df000 CR3: 00000003d9e4e001 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  read_block_for_search+0xf6/0x350 [btrfs]
  btrfs_next_old_leaf+0x242/0x650 [btrfs]
  resolve_indirect_refs+0x7cf/0x9e0 [btrfs]
  find_parent_nodes+0x4ea/0x12c0 [btrfs]
  btrfs_find_all_roots_safe+0xbf/0x130 [btrfs]
  btrfs_qgroup_account_extents+0x9d/0x390 [btrfs]
  btrfs_commit_transaction+0x4f7/0xb20 [btrfs]
  btrfs_sync_file+0x3d4/0x4d0 [btrfs]
  do_fsync+0x38/0x70
  __x64_sys_fdatasync+0x13/0x20
  do_syscall_64+0x5c/0xe0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fc47e2d72e3
 Code: Bad RIP value.
 RSP: 002b:00007fffa32098c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc47e2d72e3
 RDX: 00007fffa3209830 RSI: 00007fffa3209830 RDI: 0000000000000003
 RBP: 000000000000072e R08: 0000000000000001 R09: 0000000000000003
 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000003e8
 R13: 0000000051eb851f R14: 00007fffa3209970 R15: 00005607c4ac8b50
 irq event stamp: 0
 hardirqs last  enabled at (0): [<0000000000000000>] 0x0
 hardirqs last disabled at (0): [<ffffffffb8eb5e85>] copy_process+0x755/0x1eb0
 softirqs last  enabled at (0): [<ffffffffb8eb5e85>] copy_process+0x755/0x1eb0
 softirqs last disabled at (0): [<0000000000000000>] 0x0
 ---[ end trace 8639237550317b48 ]---
 BTRFS error (device sdc): tree first key mismatch detected, bytenr=62324736 parent_transid=94 key expected=(262,108,1351680) has=(259,108,1921024)
 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
 CPU: 2 PID: 1763215 Comm: fsstress Tainted: G        W         5.8.0-rc3-btrfs-next-64 #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:ulist_release+0x14/0x60 [btrfs]
 Code: c7 07 00 (...)
 RSP: 0018:ffffb89b47377d60 EFLAGS: 00010282
 RAX: 6b6b6b6b6b6b6b6b RBX: ffff903959b56b90 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000270024 RDI: ffff9036e2adc840
 RBP: ffff9036e2adc848 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9036e2adc840
 R13: 0000000000000015 R14: ffff9039a419ccf8 R15: ffff90395d605840
 FS:  00007fc47e1e1000(0000) GS:ffff9039ac600000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f8c1c0a51c8 CR3: 00000003d9e4e004 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  ulist_free+0x13/0x20 [btrfs]
  btrfs_qgroup_account_extents+0xf3/0x390 [btrfs]
  btrfs_commit_transaction+0x4f7/0xb20 [btrfs]
  btrfs_sync_file+0x3d4/0x4d0 [btrfs]
  do_fsync+0x38/0x70
  __x64_sys_fdatasync+0x13/0x20
  do_syscall_64+0x5c/0xe0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fc47e2d72e3
 Code: Bad RIP value.
 RSP: 002b:00007fffa32098c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc47e2d72e3
 RDX: 00007fffa3209830 RSI: 00007fffa3209830 RDI: 0000000000000003
 RBP: 000000000000072e R08: 0000000000000001 R09: 0000000000000003
 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000003e8
 R13: 0000000051eb851f R14: 00007fffa3209970 R15: 00005607c4ac8b50
 Modules linked in: dm_snapshot dm_thin_pool (...)
 ---[ end trace 8639237550317b49 ]---
 RIP: 0010:ulist_release+0x14/0x60 [btrfs]
 Code: c7 07 00 (...)
 RSP: 0018:ffffb89b47377d60 EFLAGS: 00010282
 RAX: 6b6b6b6b6b6b6b6b RBX: ffff903959b56b90 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000270024 RDI: ffff9036e2adc840
 RBP: ffff9036e2adc848 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9036e2adc840
 R13: 0000000000000015 R14: ffff9039a419ccf8 R15: ffff90395d605840
 FS:  00007fc47e1e1000(0000) GS:ffff9039ad200000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f6a776f7d40 CR3: 00000003d9e4e002 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fix this by making btrfs_find_all_roots_safe() set *roots to NULL after
it frees the ulist.

Fixes: 8da6d5815c ("Btrfs: added btrfs_find_all_roots()")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-21 21:59:15 +02:00
..
tests btrfs: kill the subvol_srcu 2020-03-23 17:02:00 +01:00
acl.c btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter 2019-04-29 19:02:44 +02:00
async-thread.c Btrfs: fix crash during unmount due to race with delayed inode workers 2020-03-23 17:01:51 +01:00
async-thread.h Btrfs: fix crash during unmount due to race with delayed inode workers 2020-03-23 17:01:51 +01:00
backref.c btrfs: fix double free on ulist after backref resolution failure 2020-07-21 21:59:15 +02:00
backref.h btrfs: rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE 2020-05-25 11:25:35 +02:00
block-group.c btrfs: fix race between block group removal and block group creation 2020-06-16 19:20:58 +02:00
block-group.h btrfs: move the block group freeze/unfreeze helpers into block-group.c 2020-05-25 11:25:30 +02:00
block-rsv.c btrfs: rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE 2020-05-25 11:25:35 +02:00
block-rsv.h btrfs: Remove __ prefix from btrfs_block_rsv_release 2020-03-23 17:01:55 +01:00
btrfs_inode.h Revert "btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK" 2020-06-09 19:21:48 +02:00
check-integrity.c btrfs: remove buffer_heads form super block mirror integrity checking 2020-03-23 17:01:40 +01:00
check-integrity.h btrfs: remove btrfsic_submit_bh() 2020-03-23 17:01:39 +01:00
compression.c btrfs: unexport btrfs_compress_set_level() 2020-05-25 11:25:37 +02:00
compression.h btrfs: unexport btrfs_compress_set_level() 2020-05-25 11:25:37 +02:00
ctree.c btrfs: convert comments to fallthrough annotations 2020-07-02 10:18:30 +02:00
ctree.h btrfs: check if a log root exists before locking the log_mutex on unlink 2020-06-16 19:22:23 +02:00
delalloc-space.c btrfs: Remove __ prefix from btrfs_block_rsv_release 2020-03-23 17:01:55 +01:00
delalloc-space.h btrfs: migrate the delalloc space stuff to it's own home 2019-07-04 17:26:17 +02:00
delayed-inode.c btrfs: use nofs allocations for running delayed items 2020-03-25 16:26:00 +01:00
delayed-inode.h btrfs: delayed-inode: Replace zero-length array with flexible-array member 2020-03-23 17:01:53 +01:00
delayed-ref.c btrfs: Remove __ prefix from btrfs_block_rsv_release 2020-03-23 17:01:55 +01:00
delayed-ref.h btrfs: migrate the delayed refs rsv code 2019-07-04 17:26:17 +02:00
dev-replace.c btrfs: sysfs, rename device_link add/remove functions 2020-03-23 17:01:35 +01:00
dev-replace.h btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
dir-item.c btrfs: remove unused parameter fs_info from btrfs_extend_item 2019-04-29 19:02:50 +02:00
discard.c btrfs: discard: add missing put when grabbing block group from unused list 2020-07-07 16:06:28 +02:00
discard.h btrfs: discard: Use the correct style for SPDX License Identifier 2020-04-20 17:43:42 +02:00
disk-io.c btrfs: reset tree root pointer after error in init_tree_roots 2020-07-02 10:27:12 +02:00
disk-io.h btrfs: simplify root lookup by id 2020-05-25 11:25:36 +02:00
export.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
export.h btrfs: export helpers for subvolume name/id resolution 2020-03-23 17:01:42 +01:00
extent_io.c btrfs: fix fatal extent_buffer readahead vs releasepage race 2020-07-02 10:18:33 +02:00
extent_io.h btrfs: constify extent_buffer in the API functions 2020-05-25 11:25:34 +02:00
extent_map.c Btrfs: fix race between using extent maps and merging them 2020-02-12 17:16:46 +01:00
extent_map.h btrfs: remove extent_map::bdev 2019-11-18 23:43:44 +01:00
extent-io-tree.h btrfs: fix corrupt log due to concurrent fsync of inodes with shared extents 2020-05-25 11:25:37 +02:00
extent-tree.c btrfs: rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE 2020-05-25 11:25:35 +02:00
file-item.c btrfs: remove useless 'fail_unlock' label from btrfs_csum_file_blocks() 2020-05-25 11:25:37 +02:00
file.c btrfs: wire up iter_file_splice_write 2020-07-09 19:57:58 +02:00
free-space-cache.c btrfs: turn space cache writeout failure messages into debug messages 2020-05-25 11:25:38 +02:00
free-space-cache.h btrfs: have multiple discard lists 2020-01-20 16:41:00 +01:00
free-space-tree.c btrfs: move the root freeing stuff into btrfs_put_root 2020-03-23 17:01:59 +01:00
free-space-tree.h btrfs: rename btrfs_block_group_cache 2019-11-18 17:51:51 +01:00
inode-item.c btrfs: Make btrfs_find_name_in_ext_backref return struct btrfs_inode_extref 2019-09-09 14:59:16 +02:00
inode-map.c btrfs: Remove __ prefix from btrfs_block_rsv_release 2020-03-23 17:01:55 +01:00
inode-map.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
inode.c btrfs: fix double put of block group with nocow 2020-07-09 17:44:26 +02:00
ioctl.c btrfs: use kfree() in btrfs_ioctl_get_subvol_info() 2020-06-16 19:24:03 +02:00
Kconfig Revert "btrfs: switch to iomap_dio_rw() for dio" 2020-06-14 01:19:02 +02:00
locking.c btrfs: add missing annotation for btrfs_tree_lock() 2020-05-25 11:25:16 +02:00
locking.h btrfs: Implement DREW lock 2020-03-23 17:01:43 +01:00
lzo.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00
Makefile Btrfs: move all reflink implementation code into its own file 2020-03-23 17:01:54 +01:00
misc.h btrfs: rename tree_entry to rb_simple_node and export it 2020-05-25 11:25:19 +02:00
ordered-data.c btrfs: drop argument tree from btrfs_lock_and_flush_ordered_range 2020-03-23 17:01:34 +01:00
ordered-data.h btrfs: drop argument tree from btrfs_lock_and_flush_ordered_range 2020-03-23 17:01:34 +01:00
orphan.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
print-tree.c btrfs: Remove unneeded semicolon 2020-01-20 16:40:55 +01:00
print-tree.h btrfs: print-tree: debugging output enhancement 2018-04-20 19:18:16 +02:00
props.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
props.h btrfs: delete unused function btrfs_set_prop_trans 2019-04-29 19:02:54 +02:00
qgroup.c btrfs: qgroup: mark qgroup inconsistent if we're inherting snapshot to a new qgroup 2020-05-25 11:25:29 +02:00
qgroup.h btrfs: destroy qgroup extent records on transaction abort 2020-02-19 00:35:54 +01:00
raid56.c btrfs: use struct_size to calculate size of raid hash table 2020-03-23 17:01:44 +01:00
raid56.h btrfs: constify map parameter for nr_parity_stripes and nr_data_stripes 2019-07-01 13:34:58 +02:00
rcu-string.h btrfs: rcu-string: Replace zero-length array with flexible-array member 2020-03-23 17:01:53 +01:00
reada.c btrfs: rename btrfs_block_group_cache 2019-11-18 17:51:51 +01:00
ref-verify.c btrfs: convert comments to fallthrough annotations 2020-07-02 10:18:30 +02:00
ref-verify.h btrfs: ref-verify: Use btrfs_ref to refactor btrfs_ref_tree_mod() 2019-04-29 19:02:49 +02:00
reflink.c btrfs: fix lost i_size update after cloning inline extent 2020-04-08 19:10:34 +02:00
reflink.h Btrfs: move all reflink implementation code into its own file 2020-03-23 17:01:54 +01:00
relocation.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
root-tree.c btrfs: simplify root lookup by id 2020-05-25 11:25:36 +02:00
scrub.c btrfs: simplify root lookup by id 2020-05-25 11:25:36 +02:00
send.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
send.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
space-info.c btrfs: fix reclaim_size counter leak after stealing from global reserve 2020-07-02 10:18:34 +02:00
space-info.h btrfs: improve global reserve stealing logic 2020-05-25 11:25:22 +02:00
struct-funcs.c btrfs: update documentation of set/get helpers 2020-05-25 11:25:35 +02:00
super.c btrfs: convert comments to fallthrough annotations 2020-07-02 10:18:30 +02:00
sysfs.c btrfs: sysfs: Use scnprintf() instead of snprintf() 2020-03-23 18:14:47 +01:00
sysfs.h btrfs: sysfs, rename device_link add/remove functions 2020-03-23 17:01:35 +01:00
transaction.c btrfs: simplify root lookup by id 2020-05-25 11:25:36 +02:00
transaction.h btrfs: improve global reserve stealing logic 2020-05-25 11:25:22 +02:00
tree-checker.c btrfs: tree-checker: remove duplicate definition of 'inode_item_err' 2020-05-25 11:25:23 +02:00
tree-checker.h btrfs: get fs_info from eb in btrfs_check_chunk_valid 2019-04-29 19:02:39 +02:00
tree-defrag.c btrfs: rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE 2020-05-25 11:25:35 +02:00
tree-log.c btrfs: check if a log root exists before locking the log_mutex on unlink 2020-06-16 19:22:23 +02:00
tree-log.h btrfs: get fs_info from trans in btrfs_set_log_full_commit 2019-04-29 19:02:41 +02:00
ulist.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
ulist.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
uuid-tree.c btrfs: simplify root lookup by id 2020-05-25 11:25:36 +02:00
volumes.c btrfs: drop stale reference to volume_mutex 2020-05-25 11:25:35 +02:00
volumes.h btrfs: convert comments to fallthrough annotations 2020-07-02 10:18:30 +02:00
xattr.c Btrfs: fix failure to persist compression property xattr deletion on fsync 2019-06-17 16:37:17 +02:00
xattr.h btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter 2019-04-29 19:02:44 +02:00
zlib.c btrfs: use larger zlib buffer for s390 hardware compression 2020-01-31 10:30:40 -08:00
zstd.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00