4.19-stable patches

added patches:
	dm-fix-mempool-null-pointer-race-when-completing-io.patch
	dm-interlock-pending-dm_io-and-dm_wait_for_bios_completion.patch

diff --git a/queue-4.19/dm-fix-mempool-null-pointer-race-when-completing-io.patch b/queue-4.19/dm-fix-mempool-null-pointer-race-when-completing-io.patch
new file mode 100644 (file)
index 0000000..fc590fe
--- /dev/null
+++ b/queue-4.19/dm-fix-mempool-null-pointer-race-when-completing-io.patch
@@ -0,0 +1,144 @@
+From d208b89401e073de986dc891037c5a668f5d5d95 Mon Sep 17 00:00:00 2001
+From: Jiazi Li <jqqlijiazi@gmail.com>
+Date: Wed, 29 Sep 2021 19:59:28 +0800
+Subject: dm: fix mempool NULL pointer race when completing IO
+
+From: Jiazi Li <jqqlijiazi@gmail.com>
+
+commit d208b89401e073de986dc891037c5a668f5d5d95 upstream.
+
+dm_io_dec_pending() calls end_io_acct() first and will then dec md
+in-flight pending count. But if a task is swapping DM table at same
+time this can result in a crash due to mempool->elements being NULL:
+
+task1                             task2
+do_resume
+ ->do_suspend
+  ->dm_wait_for_completion
+                                  bio_endio
+                                  ->clone_endio
+                                   ->dm_io_dec_pending
+                                    ->end_io_acct
+                                     ->wakeup task1
+ ->dm_swap_table
+  ->__bind
+   ->__bind_mempools
+    ->bioset_exit
+     ->mempool_exit
+                                     ->free_io
+
+[ 67.330330] Unable to handle kernel NULL pointer dereference at
+virtual address 0000000000000000
+......
+[ 67.330494] pstate: 80400085 (Nzcv daIf +PAN -UAO)
+[ 67.330510] pc : mempool_free+0x70/0xa0
+[ 67.330515] lr : mempool_free+0x4c/0xa0
+[ 67.330520] sp : ffffff8008013b20
+[ 67.330524] x29: ffffff8008013b20 x28: 0000000000000004
+[ 67.330530] x27: ffffffa8c2ff40a0 x26: 00000000ffff1cc8
+[ 67.330535] x25: 0000000000000000 x24: ffffffdada34c800
+[ 67.330541] x23: 0000000000000000 x22: ffffffdada34c800
+[ 67.330547] x21: 00000000ffff1cc8 x20: ffffffd9a1304d80
+[ 67.330552] x19: ffffffdada34c970 x18: 000000b312625d9c
+[ 67.330558] x17: 00000000002dcfbf x16: 00000000000006dd
+[ 67.330563] x15: 000000000093b41e x14: 0000000000000010
+[ 67.330569] x13: 0000000000007f7a x12: 0000000034155555
+[ 67.330574] x11: 0000000000000001 x10: 0000000000000001
+[ 67.330579] x9 : 0000000000000000 x8 : 0000000000000000
+[ 67.330585] x7 : 0000000000000000 x6 : ffffff80148b5c1a
+[ 67.330590] x5 : ffffff8008013ae0 x4 : 0000000000000001
+[ 67.330596] x3 : ffffff80080139c8 x2 : ffffff801083bab8
+[ 67.330601] x1 : 0000000000000000 x0 : ffffffdada34c970
+[ 67.330609] Call trace:
+[ 67.330616] mempool_free+0x70/0xa0
+[ 67.330627] bio_put+0xf8/0x110
+[ 67.330638] dec_pending+0x13c/0x230
+[ 67.330644] clone_endio+0x90/0x180
+[ 67.330649] bio_endio+0x198/0x1b8
+[ 67.330655] dec_pending+0x190/0x230
+[ 67.330660] clone_endio+0x90/0x180
+[ 67.330665] bio_endio+0x198/0x1b8
+[ 67.330673] blk_update_request+0x214/0x428
+[ 67.330683] scsi_end_request+0x2c/0x300
+[ 67.330688] scsi_io_completion+0xa0/0x710
+[ 67.330695] scsi_finish_command+0xd8/0x110
+[ 67.330700] scsi_softirq_done+0x114/0x148
+[ 67.330708] blk_done_softirq+0x74/0xd0
+[ 67.330716] __do_softirq+0x18c/0x374
+[ 67.330724] irq_exit+0xb4/0xb8
+[ 67.330732] __handle_domain_irq+0x84/0xc0
+[ 67.330737] gic_handle_irq+0x148/0x1b0
+[ 67.330744] el1_irq+0xe8/0x190
+[ 67.330753] lpm_cpuidle_enter+0x4f8/0x538
+[ 67.330759] cpuidle_enter_state+0x1fc/0x398
+[ 67.330764] cpuidle_enter+0x18/0x20
+[ 67.330772] do_idle+0x1b4/0x290
+[ 67.330778] cpu_startup_entry+0x20/0x28
+[ 67.330786] secondary_start_kernel+0x160/0x170
+
+Fix this by:
+1) Establishing pointers to 'struct dm_io' members in
+dm_io_dec_pending() so that they may be passed into end_io_acct()
+_after_ free_io() is called.
+2) Moving end_io_acct() after free_io().
+
+Cc: stable@vger.kernel.org
+Signed-off-by: Jiazi Li <lijiazi@xiaomi.com>
+Signed-off-by: Mike Snitzer <snitzer@redhat.com>
+Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
+Reviewed-by: Mike Snitzer <snitzer@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/md/dm.c |   17 ++++++++++-------
+ 1 file changed, 10 insertions(+), 7 deletions(-)
+
+--- a/drivers/md/dm.c
++++ b/drivers/md/dm.c
+@@ -631,21 +631,20 @@ static void start_io_acct(struct dm_io *
+                                   false, 0, &io->stats_aux);
+ }
+ 
+-static void end_io_acct(struct dm_io *io)
++static void end_io_acct(struct mapped_device *md, struct bio *bio,
++                      unsigned long start_time, struct dm_stats_aux *stats_aux)
+ {
+-      struct mapped_device *md = io->md;
+-      struct bio *bio = io->orig_bio;
+-      unsigned long duration = jiffies - io->start_time;
++      unsigned long duration = jiffies - start_time;
+       int pending;
+       int rw = bio_data_dir(bio);
+ 
+       generic_end_io_acct(md->queue, bio_op(bio), &dm_disk(md)->part0,
+-                          io->start_time);
++                          start_time);
+ 
+       if (unlikely(dm_stats_used(&md->stats)))
+               dm_stats_account_io(&md->stats, bio_data_dir(bio),
+                                   bio->bi_iter.bi_sector, bio_sectors(bio),
+-                                  true, duration, &io->stats_aux);
++                                  true, duration, stats_aux);
+ 
+       /*
+        * After this is decremented the bio must not be touched if it is
+@@ -872,6 +871,8 @@ static void dec_pending(struct dm_io *io
+       blk_status_t io_error;
+       struct bio *bio;
+       struct mapped_device *md = io->md;
++      unsigned long start_time = 0;
++      struct dm_stats_aux stats_aux;
+ 
+       /* Push-back supersedes any I/O errors */
+       if (unlikely(error)) {
+@@ -898,8 +899,10 @@ static void dec_pending(struct dm_io *io
+ 
+               io_error = io->status;
+               bio = io->orig_bio;
+-              end_io_acct(io);
++              start_time = io->start_time;
++              stats_aux = io->stats_aux;
+               free_io(md, io);
++              end_io_acct(md, bio, start_time, &stats_aux);
+ 
+               if (io_error == BLK_STS_DM_REQUEUE)
+                       return;

diff --git a/queue-4.19/dm-interlock-pending-dm_io-and-dm_wait_for_bios_completion.patch b/queue-4.19/dm-interlock-pending-dm_io-and-dm_wait_for_bios_completion.patch
new file mode 100644 (file)
index 0000000..a511a10
--- /dev/null
+++ b/queue-4.19/dm-interlock-pending-dm_io-and-dm_wait_for_bios_completion.patch
@@ -0,0 +1,44 @@
+From 9f6dc633761006f974701d4c88da71ab68670749 Mon Sep 17 00:00:00 2001
+From: Mike Snitzer <snitzer@redhat.com>
+Date: Thu, 17 Feb 2022 23:40:02 -0500
+Subject: dm: interlock pending dm_io and dm_wait_for_bios_completion
+
+From: Mike Snitzer <snitzer@redhat.com>
+
+commit 9f6dc633761006f974701d4c88da71ab68670749 upstream.
+
+Commit d208b89401e0 ("dm: fix mempool NULL pointer race when
+completing IO") didn't go far enough.
+
+When bio_end_io_acct ends the count of in-flight I/Os may reach zero
+and the DM device may be suspended. There is a possibility that the
+suspend races with dm_stats_account_io.
+
+Fix this by adding percpu "pending_io" counters to track outstanding
+dm_io. Move kicking of suspend queue to dm_io_dec_pending(). Also,
+rename md_in_flight_bios() to dm_in_flight_bios() and update it to
+iterate all pending_io counters.
+
+Fixes: d208b89401e0 ("dm: fix mempool NULL pointer race when completing IO")
+Cc: stable@vger.kernel.org
+Co-developed-by: Mikulas Patocka <mpatocka@redhat.com>
+Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
+Signed-off-by: Mike Snitzer <snitzer@redhat.com>
+Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
+Reviewed-by: Mike Snitzer <snitzer@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/md/dm.c |    2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/drivers/md/dm.c
++++ b/drivers/md/dm.c
+@@ -2475,6 +2475,8 @@ static int dm_wait_for_completion(struct
+       }
+       finish_wait(&md->wait, &wait);
+ 
++      smp_rmb(); /* paired with atomic_dec_return in end_io_acct */
++
+       return r;
+ }
+ 

diff --git a/queue-4.19/series b/queue-4.19/series
index 55715c8ffaf622882ad8b4ed0aae2450d536574e..1672d249b4369168ffd571d13a7fbd64a09f2b64 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -83,3 +83,5 @@ kvm-x86-cpuid-only-provide-cpuid-leaf-0xa-if-host-ha.patch
 nfc-netlink-fix-sleep-in-atomic-bug-when-firmware-do.patch
 mm-fix-unexpected-zeroed-page-mapping-with-zram-swap.patch
 tcp-make-sure-treq-af_specific-is-initialized.patch
+dm-fix-mempool-null-pointer-race-when-completing-io.patch
+dm-interlock-pending-dm_io-and-dm_wait_for_bios_completion.patch