From: Greg Kroah-Hartman Date: Tue, 10 May 2022 11:56:37 +0000 (+0200) Subject: 5.4-stable patches X-Git-Tag: v4.9.313~14 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d8d043f9262178e09e165a2ab11695df82f6d163;p=thirdparty%2Fkernel%2Fstable-queue.git 5.4-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-5.4/dm-fix-mempool-null-pointer-race-when-completing-io.patch b/queue-5.4/dm-fix-mempool-null-pointer-race-when-completing-io.patch new file mode 100644 index 00000000000..36aa8ea7b29 --- /dev/null +++ b/queue-5.4/dm-fix-mempool-null-pointer-race-when-completing-io.patch @@ -0,0 +1,142 @@ +From d208b89401e073de986dc891037c5a668f5d5d95 Mon Sep 17 00:00:00 2001 +From: Jiazi Li +Date: Wed, 29 Sep 2021 19:59:28 +0800 +Subject: dm: fix mempool NULL pointer race when completing IO + +From: Jiazi Li + +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 +Signed-off-by: Mike Snitzer +Signed-off-by: Mikulas Patocka +Reviewed-by: Mike Snitzer +Signed-off-by: Greg Kroah-Hartman +--- + drivers/md/dm.c | 17 ++++++++++------- + 1 file changed, 10 insertions(+), 7 deletions(-) + +--- a/drivers/md/dm.c ++++ b/drivers/md/dm.c +@@ -676,19 +676,18 @@ 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; + + 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); + + /* nudge anyone waiting on suspend queue */ + if (unlikely(wq_has_sleeper(&md->wait))) +@@ -909,6 +908,8 @@ 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)) { +@@ -935,8 +936,10 @@ 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-5.4/dm-interlock-pending-dm_io-and-dm_wait_for_bios_completion.patch b/queue-5.4/dm-interlock-pending-dm_io-and-dm_wait_for_bios_completion.patch new file mode 100644 index 00000000000..3417a9c4ec4 --- /dev/null +++ b/queue-5.4/dm-interlock-pending-dm_io-and-dm_wait_for_bios_completion.patch @@ -0,0 +1,64 @@ +From 9f6dc633761006f974701d4c88da71ab68670749 Mon Sep 17 00:00:00 2001 +From: Mike Snitzer +Date: Thu, 17 Feb 2022 23:40:02 -0500 +Subject: dm: interlock pending dm_io and dm_wait_for_bios_completion + +From: Mike Snitzer + +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 +Signed-off-by: Mikulas Patocka +Signed-off-by: Mike Snitzer +Signed-off-by: Mikulas Patocka +Reviewed-by: Mike Snitzer +Signed-off-by: Greg Kroah-Hartman +--- + drivers/md/dm.c | 10 +++++++--- + 1 file changed, 7 insertions(+), 3 deletions(-) + +--- a/drivers/md/dm.c ++++ b/drivers/md/dm.c +@@ -681,14 +681,16 @@ static void end_io_acct(struct mapped_de + { + unsigned long duration = jiffies - start_time; + +- generic_end_io_acct(md->queue, bio_op(bio), &dm_disk(md)->part0, +- 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, stats_aux); + ++ smp_wmb(); ++ ++ generic_end_io_acct(md->queue, bio_op(bio), &dm_disk(md)->part0, ++ start_time); ++ + /* nudge anyone waiting on suspend queue */ + if (unlikely(wq_has_sleeper(&md->wait))) + wake_up(&md->wait); +@@ -2494,6 +2496,8 @@ static int dm_wait_for_completion(struct + } + finish_wait(&md->wait, &wait); + ++ smp_rmb(); ++ + return r; + } + diff --git a/queue-5.4/series b/queue-5.4/series index d3b8ec5dfa4..13199e37f3b 100644 --- a/queue-5.4/series +++ b/queue-5.4/series @@ -47,3 +47,5 @@ alsa-pcm-fix-races-among-concurrent-prepare-and-hw_params-hw_free-calls.patch alsa-pcm-fix-races-among-concurrent-prealloc-proc-writes.patch alsa-pcm-fix-potential-ab-ba-lock-with-buffer_mutex-and-mmap_lock.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