This is a note to let you know that I've just added the patch titled
xfs: wait iclog complete before tearing down AIL
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xfs-wait-iclog-complete-before-tearing-down-ail.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable+bounces-42905-greg=kroah.com@xxxxxxxxxxxxxxx Wed May 1 20:42:02 2024
From: Leah Rumancik <leah.rumancik@xxxxxxxxx>
Date: Wed, 1 May 2024 11:41:04 -0700
Subject: xfs: wait iclog complete before tearing down AIL
To: stable@xxxxxxxxxxxxxxx
Cc: linux-xfs@xxxxxxxxxxxxxxx, amir73il@xxxxxxxxx, chandan.babu@xxxxxxxxxx, fred@xxxxxxxxxxxxxx, Guo Xuenan <guoxuenan@xxxxxxxxxx>, "Darrick J . Wong" <djwong@xxxxxxxxxx>, Leah Rumancik <leah.rumancik@xxxxxxxxx>
Message-ID: <20240501184112.3799035-16-leah.rumancik@xxxxxxxxx>
From: Guo Xuenan <guoxuenan@xxxxxxxxxx>
[ Upstream commit 1eb52a6a71981b80f9acbd915acd6a05a5037196 ]
Fix uaf in xfs_trans_ail_delete during xlog force shutdown.
In commit cd6f79d1fb32 ("xfs: run callbacks before waking waiters in
xlog_state_shutdown_callbacks") changed the order of running callbacks
and wait for iclog completion to avoid unmount path untimely destroy AIL.
But which seems not enough to ensue this, adding mdelay in
`xfs_buf_item_unpin` can prove that.
The reproduction is as follows. To ensure destroy AIL safely,
we should wait all xlog ioend workers done and sync the AIL.
==================================================================
BUG: KASAN: use-after-free in xfs_trans_ail_delete+0x240/0x2a0
Read of size 8 at addr ffff888023169400 by task kworker/1:1H/43
CPU: 1 PID: 43 Comm: kworker/1:1H Tainted: G W
6.1.0-rc1-00002-gc28266863c4a #137
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Workqueue: xfs-log/sda xlog_ioend_work
Call Trace:
<TASK>
dump_stack_lvl+0x4d/0x66
print_report+0x171/0x4a6
kasan_report+0xb3/0x130
xfs_trans_ail_delete+0x240/0x2a0
xfs_buf_item_done+0x7b/0xa0
xfs_buf_ioend+0x1e9/0x11f0
xfs_buf_item_unpin+0x4c8/0x860
xfs_trans_committed_bulk+0x4c2/0x7c0
xlog_cil_committed+0xab6/0xfb0
xlog_cil_process_committed+0x117/0x1e0
xlog_state_shutdown_callbacks+0x208/0x440
xlog_force_shutdown+0x1b3/0x3a0
xlog_ioend_work+0xef/0x1d0
process_one_work+0x6f9/0xf70
worker_thread+0x578/0xf30
kthread+0x28c/0x330
ret_from_fork+0x1f/0x30
</TASK>
Allocated by task 9606:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_kmalloc+0x7a/0x90
__kmalloc+0x59/0x140
kmem_alloc+0xb2/0x2f0
xfs_trans_ail_init+0x20/0x320
xfs_log_mount+0x37e/0x690
xfs_mountfs+0xe36/0x1b40
xfs_fs_fill_super+0xc5c/0x1a70
get_tree_bdev+0x3c5/0x6c0
vfs_get_tree+0x85/0x250
path_mount+0xec3/0x1830
do_mount+0xef/0x110
__x64_sys_mount+0x150/0x1f0
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 9662:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x40
__kasan_slab_free+0x105/0x1a0
__kmem_cache_free+0x99/0x2d0
kvfree+0x3a/0x40
xfs_log_unmount+0x60/0xf0
xfs_unmountfs+0xf3/0x1d0
xfs_fs_put_super+0x78/0x300
generic_shutdown_super+0x151/0x400
kill_block_super+0x9a/0xe0
deactivate_locked_super+0x82/0xe0
deactivate_super+0x91/0xb0
cleanup_mnt+0x32a/0x4a0
task_work_run+0x15f/0x240
exit_to_user_mode_prepare+0x188/0x190
syscall_exit_to_user_mode+0x12/0x30
do_syscall_64+0x42/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff888023169400
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes inside of
128-byte region [ffff888023169400, ffff888023169480)
The buggy address belongs to the physical page:
page:ffffea00008c5a00 refcount:1 mapcount:0 mapping:0000000000000000
index:0xffff888023168f80 pfn:0x23168
head:ffffea00008c5a00 order:1 compound_mapcount:0 compound_pincount:0
flags: 0x1fffff80010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff)
raw: 001fffff80010200 ffffea00006b3988 ffffea0000577a88 ffff88800f842ac0
raw: ffff888023168f80 0000000000150007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888023169300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888023169380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888023169400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888023169480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888023169500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Disabling lock debugging due to kernel taint
Fixes: cd6f79d1fb32 ("xfs: run callbacks before waking waiters in xlog_state_shutdown_callbacks")
Signed-off-by: Guo Xuenan <guoxuenan@xxxxxxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Leah Rumancik <leah.rumancik@xxxxxxxxx>
Acked-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_log.c | 36 +++++++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 11 deletions(-)
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -887,6 +887,23 @@ xlog_force_iclog(
}
/*
+ * Cycle all the iclogbuf locks to make sure all log IO completion
+ * is done before we tear down these buffers.
+ */
+static void
+xlog_wait_iclog_completion(struct xlog *log)
+{
+ int i;
+ struct xlog_in_core *iclog = log->l_iclog;
+
+ for (i = 0; i < log->l_iclog_bufs; i++) {
+ down(&iclog->ic_sema);
+ up(&iclog->ic_sema);
+ iclog = iclog->ic_next;
+ }
+}
+
+/*
* Wait for the iclog and all prior iclogs to be written disk as required by the
* log force state machine. Waiting on ic_force_wait ensures iclog completions
* have been ordered and callbacks run before we are woken here, hence
@@ -1111,6 +1128,14 @@ xfs_log_unmount(
{
xfs_log_clean(mp);
+ /*
+ * If shutdown has come from iclog IO context, the log
+ * cleaning will have been skipped and so we need to wait
+ * for the iclog to complete shutdown processing before we
+ * tear anything down.
+ */
+ xlog_wait_iclog_completion(mp->m_log);
+
xfs_buftarg_drain(mp->m_ddev_targp);
xfs_trans_ail_destroy(mp);
@@ -2114,17 +2139,6 @@ xlog_dealloc_log(
int i;
/*
- * Cycle all the iclogbuf locks to make sure all log IO completion
- * is done before we tear down these buffers.
- */
- iclog = log->l_iclog;
- for (i = 0; i < log->l_iclog_bufs; i++) {
- down(&iclog->ic_sema);
- up(&iclog->ic_sema);
- iclog = iclog->ic_next;
- }
-
- /*
* Destroy the CIL after waiting for iclog IO completion because an
* iclog EIO error will try to shut down the log, which accesses the
* CIL to wake up the waiters.
Patches currently in stable-queue which might be from kroah.com@xxxxxxxxxxxxxxx are
queue-6.1/xfs-iomap-move-delalloc-punching-to-iomap.patch
queue-6.1/xfs-fix-off-by-one-block-in-xfs_discard_folio.patch
queue-6.1/xfs-invalidate-block-device-page-cache-during-unmount.patch
queue-6.1/xfs-drop-write-error-injection-is-unfixable-remove-it.patch
queue-6.1/iomap-buffered-write-failure-should-not-truncate-the-page-cache.patch
queue-6.1/xfs-fix-super-block-buf-log-item-uaf-during-force-shutdown.patch
queue-6.1/xfs-fix-incorrect-i_nlink-caused-by-inode-racing.patch
queue-6.1/xfs-estimate-post-merge-refcounts-correctly.patch
queue-6.1/xfs-fix-log-recovery-when-unknown-rocompat-bits-are-set.patch
queue-6.1/xfs-punching-delalloc-extents-on-write-failure-is-racy.patch
queue-6.1/xfs-allow-inode-inactivation-during-a-ro-mount-log-recovery.patch
queue-6.1/iomap-write-iomap-validity-checks.patch
queue-6.1/xfs-attach-dquots-to-inode-before-reading-data-cow-fork-mappings.patch
queue-6.1/xfs-fix-sb-write-verify-for-lazysbcount.patch
queue-6.1/xfs-wait-iclog-complete-before-tearing-down-ail.patch
queue-6.1/xfs-use-byte-ranges-for-write-cleanup-ranges.patch
queue-6.1/xfs-xfs_bmap_punch_delalloc_range-should-take-a-byte-range.patch
queue-6.1/xfs-write-page-faults-in-iomap-are-not-buffered-writes.patch
queue-6.1/xfs-short-circuit-xfs_growfs_data_private-if-delta-is-zero.patch
queue-6.1/xfs-fix-incorrect-error-out-in-xfs_remove.patch
queue-6.1/xfs-invalidate-xfs_bufs-when-allocating-cow-extents.patch
queue-6.1/xfs-hoist-refcount-record-merge-predicates.patch
queue-6.1/xfs-get-root-inode-correctly-at-bulkstat.patch
queue-6.1/xfs-use-iomap_valid-method-to-detect-stale-cached-iomaps.patch
