| Message ID | 20200629193947.2705954-19-hch@lst.de (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [01/20] nfblock: stop using ->queuedata | expand |
On Mon, Jun 29, 2020 at 09:39:45PM +0200, Christoph Hellwig wrote: > Split out a __submit_bio_noacct helper for the actual de-recursion > algorithm, and simplify the loop by using a continue when we can't > enter the queue for a bio. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Reverting this commit and its dependencies, 5a6c35f9af41 block: remove direct_make_request ff93ea0ce763 block: shortcut __submit_bio_noacct for blk-mq drivers fixed the stack-out-of-bounds during boot, https://lore.kernel.org/linux-block/000000000000bcdeaa05a97280e4@google.com/ [ 55.573431][ T1373] BUG: KASAN: stack-out-of-bounds in bio_alloc_bioset+0x493/0x4a0 bio_alloc_bioset+0x493/0x4a0: bio_list_empty at include/linux/bio.h:561 (inlined by) bio_alloc_bioset at block/bio.c:482 [ 55.581140][ T1373] Read of size 8 at addr ffffc9000a7df1e0 by task mount/1373 [ 55.588409][ T1373] [ 55.590615][ T1373] CPU: 2 PID: 1373 Comm: mount Not tainted 5.8.0-rc3-next-20200702 #2 [ 55.598672][ T1373] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 [ 55.607972][ T1373] Call Trace: [ 55.607980][ T1373] dump_stack+0x9d/0xe0 [ 55.607984][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.607992][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.625007][ T1373] print_address_description.constprop.8.cold.10+0x56/0x44e [ 55.632191][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.637100][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.642011][ T1373] kasan_report.cold.11+0x37/0x7c [ 55.646923][ T1373] ? bio_alloc_bioset+0x493/0x4a0 [ 55.651968][ T1373] bio_alloc_bioset+0x493/0x4a0 [ 55.651971][ T1373] ? bvec_alloc+0x290/0x290 [ 55.651975][ T1373] ? mark_lock+0x147/0x1800 [ 55.651978][ T1373] ? mark_lock+0x147/0x1800 [ 55.651981][ T1373] bio_clone_fast+0xe/0x30 [ 55.651983][ T1373] bio_split+0x8a/0x4c0 [ 55.651986][ T1373] ? print_irqtrace_events+0x270/0x270 [ 55.651990][ T1373] __blk_queue_split+0xc42/0x13e0 [ 55.651998][ T1373] ? __lock_acquire+0xc57/0x4da0 Startin[ 55.693322][ T1373] ? __blk_rq_map_sg+0x14c0/0x14c0 [ 55.699711][ T1373] ? lockdep_hardirqs_on_prepare+0x550/0x550 [ 55.705602][ T1373] ? mark_held_locks+0xb0/0x110 [ 55.705605][ T1373] ? lockdep_hardirqs_on_prepare+0x550/0x550 [ 55.705608][ T1373] ? lockdep_hardirqs_on_prepare+0x550/0x550 [ 55.705611][ T1373] ? find_held_lock+0x33/0x1c0 [ 55.705614][ T1373] ? find_held_lock+0x33/0x1c0 [ 55.705618][ T1373] blk_mq_submit_bio+0x19e/0x1e20 [ 55.705621][ T1373] ? lock_downgrade+0x720/0x720 [ 55.705624][ T1373] ? blk_mq_try_issue_directly+0x140/0x140 [ 55.705628][ T1373] ? rcu_read_lock_sched_held+0xaa/0xd0 [ 55.705631][ T1373] ? rcu_read_lock_bh_held+0xc0/0xc0 [ 55.705635][ T1373] ? blk_queue_enter+0x83c/0x9a0 [ 55.705647][ T1373] ? submit_bio_checks+0x1cc0/0x1cc0 [ 55.767384][ T1373] submit_bio_noacct+0x9c0/0xeb0 [ 55.772212][ T1373] ? blk_queue_enter+0x9a0/0x9a0 [ 55.777038][ T1373] ? lockdep_hardirqs_on_prepare+0x550/0x550 [ 55.782913][ T1373] ? trace_hardirqs_on+0x20/0x1b5 [ 55.787825][ T1373] ? submit_bio+0xe7/0x480 [ 55.792125][ T1373] submit_bio+0xe7/0x480 [ 55.796252][ T1373] ? bio_associate_blkg_from_css+0x4a3/0xd30 [ 55.802124][ T1373] ? submit_bio_noacct+0xeb0/0xeb0 [ 55.807124][ T1373] ? lock_downgrade+0x720/0x720 [ 55.811862][ T1373] ? rcu_read_unlock+0x50/0x50 [ 55.816512][ T1373] ? lockdep_init_map_waits+0x267/0x7b0 [ 55.821948][ T1373] ? lockdep_init_map_waits+0x267/0x7b0 g LVM event acti[ 55.827386][ T1373] ? __raw_spin_lock_init+0x34/0x100 [ 55.833957][ T1373] submit_bio_wait+0xf9/0x200 vation on device[ 55.838521][ T1373] ? submit_bio_wait_endio+0x30/0x30 [ 55.845091][ T1373] xfs_rw_bdev+0x3ca/0x4d0 [ 55.849396][ T1373] xlog_do_io+0x149/0x320 [ 55.853611][ T1373] xlog_bread+0x1e/0xb0 [ 55.857651][ T1373] xlog_find_verify_log_record+0xba/0x4c0 [ 55.863264][ T1373] ? xlog_header_check_mount+0xb0/0xb0 [ 55.868615][ T1373] xlog_find_zeroed+0x2bc/0x4c0 8:3... [ 55.873356][ T1373] ? print_irqtrace_events+0x270/0x270 [ 55.880093][ T1373] ? xlog_find_verify_log_record+0x4c0/0x4c0 [ 55.885966][ T1373] ? __lock_acquire+0x1920/0x4da0 [ 55.890881][ T1373] xlog_find_head+0xd4/0x790 [ 55.895355][ T1373] ? xlog_find_zeroed+0x4c0/0x4c0 [ 55.900269][ T1373] ? rcu_read_lock_sched_held+0xaa/0xd0 [ 55.905708][ T1373] ? rcu_read_lock_bh_held+0xc0/0xc0 [ 55.910885][ T1373] ? sugov_update_single+0x18d/0x4f0 [ 55.916058][ T1373] xlog_find_tail+0xc2/0x810 [ 55.920534][ T1373] ? mark_lock+0x147/0x1800 [ 55.924921][ T1373] ? xlog_verify_head+0x4c0/0x4c0 [ 55.929834][ T1373] ? debug_show_held_locks+0x30/0x50 [ 55.935007][ T1373] ? print_irqtrace_events+0x270/0x270 [ 55.940358][ T1373] ? try_to_wake_up+0x6d1/0xf40 [ 55.945094][ T1373] ? mark_held_locks+0xb0/0x110 [ 55.949835][ T1373] ? lockdep_hardirqs_on_prepare+0x38c/0x550 [ 55.955708][ T1373] ? _raw_spin_unlock_irqrestore+0x39/0x40 [ 55.961410][ T1373] ? trace_hardirqs_on+0x20/0x1b5 [ 55.966324][ T1373] xlog_recover+0x7c/0x480 [ 55.970627][ T1373] ? xlog_buf_readahead+0x110/0x110 [ 55.975715][ T1373] ? migrate_swap_stop+0xbf0/0xbf0 [ 55.980718][ T1373] ? lockdep_init_map_waits+0x267/0x7b0 [ 55.986156][ T1373] ? __raw_spin_lock_init+0x34/0x100 [ 55.991333][ T1373] xfs_log_mount+0x541/0x660 [ 55.995809][ T1373] xfs_mountfs+0xccd/0x1a00 [ 56.000202][ T1373] ? queue_work_node+0x190/0x190 [ 56.005028][ T1373] ? rcu_read_lock_sched_held+0xaa/0xd0 [ 56.010466][ T1373] ? xfs_default_resblks+0x50/0x50 [ 56.015464][ T1373] ? xfs_filestream_get_parent+0xa0/0xa0 [ 56.020989][ T1373] ? init_timer_key+0x285/0x320 [ 56.025727][ T1373] ? lockdep_init_map_waits+0x267/0x7b0 [ 56.031165][ T1373] ? xfs_filestream_get_parent+0xa0/0xa0 [ 56.036689][ T1373] ? xfs_mru_cache_create+0x358/0x560 [ 56.041951][ T1373] xfs_fc_fill_super+0x6d3/0xd50 [ 56.046777][ T1373] get_tree_bdev+0x40a/0x690 [ 56.051257][ T1373] ? xfs_fs_inode_init_once+0xc0/0xc0 [ 56.056523][ T1373] vfs_get_tree+0x84/0x2c0 [ 56.060827][ T1373] do_mount+0xf93/0x1630 [ 56.064953][ T1373] ? rcu_read_lock_bh_held+0xc0/0xc0 [ 56.070129][ T1373] ? copy_mount_string+0x20/0x20 [ 56.074956][ T1373] ? _copy_from_user+0xbe/0x100 [ 56.079696][ T1373] ? memdup_user+0x4f/0x80 [ 56.083999][ T1373] __x64_sys_mount+0x15d/0x1b0 2m OK ] St[ 56.088654][ T1373] do_syscall_64+0x5f/0x310 [ 56.094437][ T1373] ? trace_hardirqs_off+0x12/0x1a0 [ 56.099439][ T1373] ? asm_exc_page_fault+0x8/0x30 [ 56.104267][ T1373] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 56.110055][ T1373] RIP: 0033:0x7f3bc2c8a9ee [ 56.114357][ T1373] Code: Bad RIP value. [ 56.118309][ T1373] RSP: 002b:00007fffd4675718 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 arted File Syste[ 56.126629][ T1373] RAX: ffffffffffffffda RBX: 000055a59d34c9c0 RCX: 00007f3bc2c8a9ee [ 56.135900][ T1373] RDX: 000055a59d34cba0 RSI: 000055a59d34cc00 RDI: 000055a59d34e900 [ 56.143779][ T1373] RBP: 00007f3bc3a36184 R08: 0000000000000000 R09: 0000000000000003 [ 56.151661][ T1373] R10: 00000000c0ed0000 R11: 0000000000000246 R12: 0000000000000000 [ 56.159541][ T1373] R13: 00000000c0ed0000 R14: 000055a59d34e900 R15: 000055a59d34cba0 [ 56.167422][ T1373] [ 56.169626][ T1373] [ 56.171831][ T1373] addr ffffc9000a7df1e0 is located in stack of task mount/1373 at offset 48 in frame: [ 56.181287][ T1373] submit_bio_noacct+0x0/0xeb0 submit_bio_noacct at block/blk-core.c:1198 [ 56.185939][ T1373] [ 56.188144][ T1373] this frame has 2 objects: m Check on /dev/[ 56.192532][ T1373] [32, 48) 'bio_list' [ 56.192534][ T1373] [96, 128) 'bio_list_on_stack' [ 56.197872][ T1373] [ 56.204894][ T1373] Memory state around the buggy address: [ 56.210420][ T1373] ffffc9000a7df080: f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 f2 f2 00 00 00 [ 56.218389][ T1373] ffffc9000a7df100: 00 00 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 disk/by-uuid/D10[ 56.226359][ T1373] >ffffc9000a7df180: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2 [ 56.235718][ T1373] ^ [ 56.242817][ T1373] ffffc9000a7df200: f2 f2 00 00 00 00 f3 f3 f3 f3 00 00 00 00 00 00 [ 56.250790][ T1373] ffffc9000a7df280: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f2 [ 56.258757][ T1373] ================================================================== > --- > block/blk-core.c | 131 +++++++++++++++++++++++++---------------------- > 1 file changed, 71 insertions(+), 60 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index 1caeb01e127768..b82f48c86e6f7a 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1085,6 +1085,74 @@ static blk_qc_t do_make_request(struct bio *bio) > return ret; > } > > +/* > + * The loop in this function may be a bit non-obvious, and so deserves some > + * explanation: > + * > + * - Before entering the loop, bio->bi_next is NULL (as all callers ensure > + * that), so we have a list with a single bio. > + * - We pretend that we have just taken it off a longer list, so we assign > + * bio_list to a pointer to the bio_list_on_stack, thus initialising the > + * bio_list of new bios to be added. ->submit_bio() may indeed add some more > + * bios through a recursive call to submit_bio_noacct. If it did, we find a > + * non-NULL value in bio_list and re-enter the loop from the top. > + * - In this case we really did just take the bio of the top of the list (no > + * pretending) and so remove it from bio_list, and call into ->submit_bio() > + * again. > + * > + * bio_list_on_stack[0] contains bios submitted by the current ->submit_bio. > + * bio_list_on_stack[1] contains bios that were submitted before the current > + * ->submit_bio_bio, but that haven't been processed yet. > + */ > +static blk_qc_t __submit_bio_noacct(struct bio *bio) > +{ > + struct bio_list bio_list_on_stack[2]; > + blk_qc_t ret = BLK_QC_T_NONE; > + > + BUG_ON(bio->bi_next); > + > + bio_list_init(&bio_list_on_stack[0]); > + current->bio_list = bio_list_on_stack; > + > + do { > + struct request_queue *q = bio->bi_disk->queue; > + struct bio_list lower, same; > + > + if (unlikely(bio_queue_enter(bio) != 0)) > + continue; > + > + /* > + * Create a fresh bio_list for all subordinate requests. > + */ > + bio_list_on_stack[1] = bio_list_on_stack[0]; > + bio_list_init(&bio_list_on_stack[0]); > + > + ret = do_make_request(bio); > + > + /* > + * Sort new bios into those for a lower level and those for the > + * same level. > + */ > + bio_list_init(&lower); > + bio_list_init(&same); > + while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) > + if (q == bio->bi_disk->queue) > + bio_list_add(&same, bio); > + else > + bio_list_add(&lower, bio); > + > + /* > + * Now assemble so we handle the lowest level first. > + */ > + bio_list_merge(&bio_list_on_stack[0], &lower); > + bio_list_merge(&bio_list_on_stack[0], &same); > + bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); > + } while ((bio = bio_list_pop(&bio_list_on_stack[0]))); > + > + current->bio_list = NULL; > + return ret; > +} > + > /** > * submit_bio_noacct - re-submit a bio to the block device layer for I/O > * @bio: The bio describing the location in memory and on the device. > @@ -1096,17 +1164,8 @@ static blk_qc_t do_make_request(struct bio *bio) > */ > blk_qc_t submit_bio_noacct(struct bio *bio) > { > - /* > - * bio_list_on_stack[0] contains bios submitted by the current > - * ->submit_bio. > - * bio_list_on_stack[1] contains bios that were submitted before the > - * current ->submit_bio_bio, but that haven't been processed yet. > - */ > - struct bio_list bio_list_on_stack[2]; > - blk_qc_t ret = BLK_QC_T_NONE; > - > if (!submit_bio_checks(bio)) > - goto out; > + return BLK_QC_T_NONE; > > /* > * We only want one ->submit_bio to be active at a time, else > @@ -1120,58 +1179,10 @@ blk_qc_t submit_bio_noacct(struct bio *bio) > */ > if (current->bio_list) { > bio_list_add(¤t->bio_list[0], bio); > - goto out; > + return BLK_QC_T_NONE; > } > > - /* following loop may be a bit non-obvious, and so deserves some > - * explanation. > - * Before entering the loop, bio->bi_next is NULL (as all callers > - * ensure that) so we have a list with a single bio. > - * We pretend that we have just taken it off a longer list, so > - * we assign bio_list to a pointer to the bio_list_on_stack, > - * thus initialising the bio_list of new bios to be > - * added. ->submit_bio() may indeed add some more bios > - * through a recursive call to submit_bio_noacct. If it > - * did, we find a non-NULL value in bio_list and re-enter the loop > - * from the top. In this case we really did just take the bio > - * of the top of the list (no pretending) and so remove it from > - * bio_list, and call into ->submit_bio() again. > - */ > - BUG_ON(bio->bi_next); > - bio_list_init(&bio_list_on_stack[0]); > - current->bio_list = bio_list_on_stack; > - do { > - struct request_queue *q = bio->bi_disk->queue; > - > - if (likely(bio_queue_enter(bio) == 0)) { > - struct bio_list lower, same; > - > - /* Create a fresh bio_list for all subordinate requests */ > - bio_list_on_stack[1] = bio_list_on_stack[0]; > - bio_list_init(&bio_list_on_stack[0]); > - ret = do_make_request(bio); > - > - /* sort new bios into those for a lower level > - * and those for the same level > - */ > - bio_list_init(&lower); > - bio_list_init(&same); > - while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) > - if (q == bio->bi_disk->queue) > - bio_list_add(&same, bio); > - else > - bio_list_add(&lower, bio); > - /* now assemble so we handle the lowest level first */ > - bio_list_merge(&bio_list_on_stack[0], &lower); > - bio_list_merge(&bio_list_on_stack[0], &same); > - bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); > - } > - bio = bio_list_pop(&bio_list_on_stack[0]); > - } while (bio); > - current->bio_list = NULL; /* deactivate */ > - > -out: > - return ret; > + return __submit_bio_noacct(bio); > } > EXPORT_SYMBOL(submit_bio_noacct); > > -- > 2.26.2 >
On Thu, Jul 02, 2020 at 10:10:10AM -0400, Qian Cai wrote: > On Mon, Jun 29, 2020 at 09:39:45PM +0200, Christoph Hellwig wrote: > > Split out a __submit_bio_noacct helper for the actual de-recursion > > algorithm, and simplify the loop by using a continue when we can't > > enter the queue for a bio. > > > > Signed-off-by: Christoph Hellwig <hch@lst.de> > > Reverting this commit and its dependencies, > > 5a6c35f9af41 block: remove direct_make_request > ff93ea0ce763 block: shortcut __submit_bio_noacct for blk-mq drivers > > fixed the stack-out-of-bounds during boot, > > https://lore.kernel.org/linux-block/000000000000bcdeaa05a97280e4@google.com/ Yikes. bio_alloc_bioset pokes into bio_list[1] in a totally undocumented way. But even with that the problem should only show up with "block: shortcut __submit_bio_noacct for blk-mq drivers". Can you try this patch? diff --git a/block/blk-core.c b/block/blk-core.c index bf882b8d84450c..9f1bf8658b611a 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1155,11 +1155,10 @@ static blk_qc_t __submit_bio_noacct(struct bio *bio) static blk_qc_t __submit_bio_noacct_mq(struct bio *bio) { struct gendisk *disk = bio->bi_disk; - struct bio_list bio_list; + struct bio_list bio_list[2] = { }; blk_qc_t ret = BLK_QC_T_NONE; - bio_list_init(&bio_list); - current->bio_list = &bio_list; + current->bio_list = bio_list; do { WARN_ON_ONCE(bio->bi_disk != disk); @@ -1174,7 +1173,7 @@ static blk_qc_t __submit_bio_noacct_mq(struct bio *bio) } ret = blk_mq_submit_bio(bio); - } while ((bio = bio_list_pop(&bio_list))); + } while ((bio = bio_list_pop(&bio_list[0]))); current->bio_list = NULL; return ret;
On Thu, 2 Jul 2020 at 19:40, Qian Cai <cai@lca.pw> wrote: > > On Mon, Jun 29, 2020 at 09:39:45PM +0200, Christoph Hellwig wrote: > > Split out a __submit_bio_noacct helper for the actual de-recursion > > algorithm, and simplify the loop by using a continue when we can't > > enter the queue for a bio. > > > > Signed-off-by: Christoph Hellwig <hch@lst.de> Kernel BUG: on arm64 and x86_64 devices running linux next-rc3-next-20200702 with KASAN config enabled. While running mkfs -t ext4. metadata: git branch: master git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git commit: d37d57041350dff35dd17cbdf9aef4011acada38 git describe: next-20200702 make_kernelversion: 5.8.0-rc3 kernel-config: https://builds.tuxbuild.com/DnjQHvYrx586eUoFxtYZxQ/kernel.config steps to reproduce: # mkfs -t ext4 /dev/disk/by-id/ata-SanDisk_SDSSDA120G_165193445014 BUG: KASAN: stack-out-of-bounds in bio_alloc_bioset+0x28c/0x2c8 [ 59.398307] Read of size 8 at addr ffff0009084277e0 by task mkfs.ext4/417 [ 59.405121] [ 59.406644] CPU: 5 PID: 417 Comm: mkfs.ext4 Not tainted 5.8.0-rc3-next-20200702 #1 [ 59.414248] Hardware name: ARM Juno development board (r2) (DT) [ 59.420195] Call trace: [ 59.422683] dump_backtrace+0x0/0x2b8 [ 59.426386] show_stack+0x18/0x28 [ 59.429741] dump_stack+0xec/0x144 [ 59.433183] print_address_description.isra.0+0x6c/0x448 [ 59.438531] kasan_report+0x134/0x200 [ 59.442226] __asan_load8+0x9c/0xd8 [ 59.445751] bio_alloc_bioset+0x28c/0x2c8 [ 59.449796] bio_clone_fast+0x28/0x98 [ 59.453492] bio_split+0x64/0x138 [ 59.456842] __blk_queue_split+0x534/0x698 [ 59.460979] blk_mq_submit_bio+0x10c/0x680 [ 59.465118] submit_bio_noacct+0x57c/0x640 [ 59.469253] submit_bio+0xc0/0x358 [ 59.472688] submit_bio_wait+0xc0/0x110 [ 59.476561] blkdev_issue_discard+0xd0/0x138 [ 59.480877] blk_ioctl_discard+0x1b8/0x238 [ 59.485008] blkdev_common_ioctl+0x594/0xd38 [ 59.489312] blkdev_ioctl+0x130/0x578 [ 59.493010] block_ioctl+0x78/0x98 [ 59.496453] ksys_ioctl+0xb8/0xf8 [ 59.499808] __arm64_sys_ioctl+0x44/0x60 [ 59.503781] el0_svc_common.constprop.0+0xa4/0x1e0 [ 59.508615] do_el0_svc+0x38/0xa0 [ 59.511967] el0_sync_handler+0x98/0x1a8 [ 59.515922] el0_sync+0x158/0x180 [ 59.519255] [ 59.520761] The buggy address belongs to the page: [ 59.525590] page:fffffe00240109c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 59.533895] flags: 0x2ffff00000000000() [ 59.537779] raw: 2ffff00000000000 0000000000000000 fffffe00240109c8 0000000000000000 [ 59.545575] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 59.553352] page dumped because: kasan: bad access detected [ 59.558947] [ 59.560463] addr ffff0009084277e0 is located in stack of task mkfs.ext4/417 at offset 48 in frame: [ 59.569475] submit_bio_noacct+0x0/0x640 [ 59.573423] [ 59.574930] this frame has 2 objects: [ 59.578624] [32, 48) 'bio_list' [ 59.578644] [64, 96) 'bio_list_on_stack' [ 59.581889] [ 59.587412] Memory state around the buggy address: [ 59.592243] ffff000908427680: 00 00 00 f2 00 00 00 f2 f2 f2 00 00 00 00 00 f3 [ 59.599510] ffff000908427700: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 [ 59.606777] >ffff000908427780: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 00 00 [ 59.614031] ^ [ 59.620427] ffff000908427800: 00 00 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 [ 59.627694] ffff000908427880: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 f3 f3 [ 59.634946] ================================================================== [ 59.642198] Disabling lock debugging due to kernel taint Kernel BUG on x86_64: [ 17.809563] ================================================================== [ 17.816786] BUG: KASAN: stack-out-of-bounds in bio_alloc_bioset+0x31f/0x340 [ 17.823750] Read of size 8 at addr ffff888225f9f450 by task systemd-udevd/361 [ 17.830881] [ 17.832384] CPU: 0 PID: 361 Comm: systemd-udevd Not tainted 5.8.0-rc3-next-20200702 #1 [ 17.840294] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 17.847686] Call Trace: [ 17.850143] dump_stack+0x84/0xba [ 17.853462] print_address_description.constprop.0+0x1f/0x210 [ 17.859212] ? _raw_spin_lock_irqsave+0x7c/0xd0 [ 17.859214] ? _raw_write_lock_irqsave+0xd0/0xd0 [ 17.859217] ? bio_alloc_bioset+0x31f/0x340 [ 17.859220] kasan_report.cold+0x37/0x7c [ 17.859222] ? bio_alloc_bioset+0x31f/0x340 [ 17.859224] __asan_load8+0x86/0xb0 [ 17.859226] bio_alloc_bioset+0x31f/0x340 [ 17.859228] ? bvec_alloc+0x160/0x160 [ 17.859230] ? bio_alloc_bioset+0x253/0x340 [ 17.859232] ? mpage_alloc.isra.0+0x37/0x120 [ 17.859234] ? do_mpage_readpage+0x740/0xd40 [ 17.859236] ? mpage_readahead+0x196/0x280 [ 17.859238] ? blkdev_readahead+0x10/0x20 [ 17.859241] ? read_pages+0x149/0x470 [ 17.859243] ? page_cache_readahead_unbounded+0x2de/0x360 [ 17.859246] ? __do_page_cache_readahead+0x6c/0x80 [ 17.859248] bio_clone_fast+0x14/0x30 [ 17.859250] bio_split+0x64/0x1b0 [ 17.859252] __blk_queue_split+0x417/0x8d0 [ 17.859255] ? __blk_rq_map_sg+0x820/0x820 [ 17.859258] ? kmem_cache_alloc+0xc6/0x4b0 [ 17.859260] ? mempool_alloc_slab+0x12/0x20 [ 17.859262] blk_mq_submit_bio+0x150/0xb90 [ 17.859265] ? blk_mq_try_issue_directly+0xe0/0xe0 [ 17.859267] ? blk_queue_enter+0xea/0x460 [ 17.859269] ? submit_bio_checks+0x4cc/0xa00 [ 17.859272] ? bio_add_page+0x78/0x110 [ 17.859274] submit_bio_noacct+0x5ff/0x6c0 [ 17.859276] ? mpage_alloc.isra.0+0xab/0x120 [ 17.859279] ? blk_queue_enter+0x460/0x460 [ 17.859281] ? do_mpage_readpage+0xc02/0xd40 [ 17.859283] submit_bio+0xb5/0x2e0 [ 17.859286] ? submit_bio_noacct+0x6c0/0x6c0 [ 17.859288] ? __disk_get_part+0x3d/0x50 [ 17.859290] mpage_readahead+0x227/0x280 [ 17.859293] ? do_mpage_readpage+0xd40/0xd40 [ 17.859295] ? bdev_evict_inode+0x130/0x130 [ 17.859297] ? find_get_pages_contig+0x340/0x340 [ 17.859299] blkdev_readahead+0x10/0x20 [ 17.859302] read_pages+0x149/0x470 [ 17.859304] ? lru_cache_add+0xde/0xf0 [ 17.859306] ? read_cache_pages+0x280/0x280 [ 17.859309] ? add_to_page_cache_locked+0x10/0x10 [ 17.859310] ? alloc_pages_current+0x98/0x110 [ 17.859313] page_cache_readahead_unbounded+0x2de/0x360 [ 17.859316] ? read_pages+0x470/0x470 [ 17.859319] ? xas_load+0xee/0x110 [ 17.859321] ? find_get_entry+0xbf/0x250 [ 17.859323] __do_page_cache_readahead+0x6c/0x80 [ 17.859326] force_page_cache_readahead+0xee/0x180 [ 17.859329] page_cache_sync_readahead+0x131/0x140 [ 17.859331] generic_file_buffered_read+0x698/0x1130 [ 17.859334] ? get_page_from_freelist+0x1b13/0x1e60 [ 17.859337] ? pagecache_get_page+0x3a0/0x3a0 [ 17.859340] ? __isolate_free_page+0x210/0x210 [ 17.859342] ? __ia32_sys_mmap_pgoff+0x90/0x90 [ 17.859345] generic_file_read_iter+0x17f/0x1f0 [ 17.859347] ? memory_high_write+0x1c0/0x1c0 [ 17.859349] blkdev_read_iter+0x76/0x90 [ 17.859352] new_sync_read+0x298/0x3c0 [ 17.859354] ? __ia32_sys_llseek+0x230/0x230 [ 17.859357] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 17.859359] ? fsnotify+0x12c/0x5f0 [ 17.859361] ? __vfs_read+0x30/0x90 [ 17.859363] __vfs_read+0x76/0x90 [ 17.859365] vfs_read+0xc8/0x1e0 [ 17.859368] ksys_read+0xc8/0x170 [ 17.859370] ? kernel_write+0xc0/0xc0 [ 17.859372] ? syscall_trace_enter+0x166/0x280 [ 17.859375] __x64_sys_read+0x3e/0x50 [ 17.859377] do_syscall_64+0x43/0x70 [ 17.859379] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 17.859381] RIP: 0033:0x7fe23cf4b56e [ 17.859382] Code: Bad RIP value. [ 17.859383] RSP: 002b:00007fff586583c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 17.859386] RAX: ffffffffffffffda RBX: 00005620318bd8a0 RCX: 00007fe23cf4b56e [ 17.859387] RDX: 0000000000040000 RSI: 00007fe23dd56038 RDI: 000000000000000f [ 17.859388] RBP: 0000000000040000 R08: 00007fe23dd56010 R09: 0000000000000000 [ 17.859390] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000040000 [ 17.859391] R13: 00005620318bd8f0 R14: 00007fe23dd56028 R15: 00007fe23dd56010 [ 17.859392] [ 17.859393] The buggy address belongs to the page: [ 17.859396] page:ffffea000897e7c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 17.859397] flags: 0x200000000000000() [ 17.859400] raw: 0200000000000000 0000000000000000 ffffea000897e7c8 0000000000000000 [ 17.859403] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 17.859403] page dumped because: kasan: bad access detected [ 17.859404] [ 17.859406] addr ffff888225f9f450 is located in stack of task systemd-udevd/361 at offset 48 in frame: [ 17.859408] submit_bio_noacct+0x0/0x6c0 [ 17.859409] [ 17.859410] this frame has 2 objects: [ 17.859412] [32, 48) 'bio_list' [ 17.859414] [64, 96) 'bio_list_on_stack' [ 17.859414] [ 17.859415] Memory state around the buggy address: [ 17.859417] ffff888225f9f300: f2 00 00 00 f2 00 00 00 f2 f2 f2 00 00 00 00 00 [ 17.859418] ffff888225f9f380: f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 [ 17.859420] >ffff888225f9f400: 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 00 00 00 00 [ 17.859421] ^ [ 17.859422] ffff888225f9f480: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 [ 17.859424] ffff888225f9f500: 00 00 00 f1 f1 f1 f1 00 00 00 00 f3 f3 f3 f3 00 [ 17.859425] ================================================================== [ 17.859425] Disabling lock debugging due to kernel taint
On Thu, 2 Jul 2020 at 20:45, Christoph Hellwig <hch@lst.de> wrote: > > On Thu, Jul 02, 2020 at 10:10:10AM -0400, Qian Cai wrote: > > On Mon, Jun 29, 2020 at 09:39:45PM +0200, Christoph Hellwig wrote: > > > Split out a __submit_bio_noacct helper for the actual de-recursion > > > algorithm, and simplify the loop by using a continue when we can't > > > enter the queue for a bio. > > > > > > Signed-off-by: Christoph Hellwig <hch@lst.de> > > > > Reverting this commit and its dependencies, > > > > 5a6c35f9af41 block: remove direct_make_request > > ff93ea0ce763 block: shortcut __submit_bio_noacct for blk-mq drivers > > > > fixed the stack-out-of-bounds during boot, > > > > https://lore.kernel.org/linux-block/000000000000bcdeaa05a97280e4@google.com/ > > Yikes. bio_alloc_bioset pokes into bio_list[1] in a totally > undocumented way. But even with that the problem should only show > up with "block: shortcut __submit_bio_noacct for blk-mq drivers". > > Can you try this patch? Applied your patch on top of linux-next 20200702 and tested on arm64 and x86_64 devices and the reported BUG fixed. Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> > > diff --git a/block/blk-core.c b/block/blk-core.c > index bf882b8d84450c..9f1bf8658b611a 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1155,11 +1155,10 @@ static blk_qc_t __submit_bio_noacct(struct bio *bio) > static blk_qc_t __submit_bio_noacct_mq(struct bio *bio) > { > struct gendisk *disk = bio->bi_disk; > - struct bio_list bio_list; > + struct bio_list bio_list[2] = { }; > blk_qc_t ret = BLK_QC_T_NONE; > > - bio_list_init(&bio_list); > - current->bio_list = &bio_list; > + current->bio_list = bio_list; > > do { > WARN_ON_ONCE(bio->bi_disk != disk); > @@ -1174,7 +1173,7 @@ static blk_qc_t __submit_bio_noacct_mq(struct bio *bio) > } > > ret = blk_mq_submit_bio(bio); > - } while ((bio = bio_list_pop(&bio_list))); > + } while ((bio = bio_list_pop(&bio_list[0]))); > > current->bio_list = NULL; > return ret; ref: https://lkft.validation.linaro.org/scheduler/job/1538359#L288 https://lkft.validation.linaro.org/scheduler/job/1538360#L572 - Naresh
diff --git a/block/blk-core.c b/block/blk-core.c index 1caeb01e127768..b82f48c86e6f7a 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1085,6 +1085,74 @@ static blk_qc_t do_make_request(struct bio *bio) return ret; } +/* + * The loop in this function may be a bit non-obvious, and so deserves some + * explanation: + * + * - Before entering the loop, bio->bi_next is NULL (as all callers ensure + * that), so we have a list with a single bio. + * - We pretend that we have just taken it off a longer list, so we assign + * bio_list to a pointer to the bio_list_on_stack, thus initialising the + * bio_list of new bios to be added. ->submit_bio() may indeed add some more + * bios through a recursive call to submit_bio_noacct. If it did, we find a + * non-NULL value in bio_list and re-enter the loop from the top. + * - In this case we really did just take the bio of the top of the list (no + * pretending) and so remove it from bio_list, and call into ->submit_bio() + * again. + * + * bio_list_on_stack[0] contains bios submitted by the current ->submit_bio. + * bio_list_on_stack[1] contains bios that were submitted before the current + * ->submit_bio_bio, but that haven't been processed yet. + */ +static blk_qc_t __submit_bio_noacct(struct bio *bio) +{ + struct bio_list bio_list_on_stack[2]; + blk_qc_t ret = BLK_QC_T_NONE; + + BUG_ON(bio->bi_next); + + bio_list_init(&bio_list_on_stack[0]); + current->bio_list = bio_list_on_stack; + + do { + struct request_queue *q = bio->bi_disk->queue; + struct bio_list lower, same; + + if (unlikely(bio_queue_enter(bio) != 0)) + continue; + + /* + * Create a fresh bio_list for all subordinate requests. + */ + bio_list_on_stack[1] = bio_list_on_stack[0]; + bio_list_init(&bio_list_on_stack[0]); + + ret = do_make_request(bio); + + /* + * Sort new bios into those for a lower level and those for the + * same level. + */ + bio_list_init(&lower); + bio_list_init(&same); + while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) + if (q == bio->bi_disk->queue) + bio_list_add(&same, bio); + else + bio_list_add(&lower, bio); + + /* + * Now assemble so we handle the lowest level first. + */ + bio_list_merge(&bio_list_on_stack[0], &lower); + bio_list_merge(&bio_list_on_stack[0], &same); + bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); + } while ((bio = bio_list_pop(&bio_list_on_stack[0]))); + + current->bio_list = NULL; + return ret; +} + /** * submit_bio_noacct - re-submit a bio to the block device layer for I/O * @bio: The bio describing the location in memory and on the device. @@ -1096,17 +1164,8 @@ static blk_qc_t do_make_request(struct bio *bio) */ blk_qc_t submit_bio_noacct(struct bio *bio) { - /* - * bio_list_on_stack[0] contains bios submitted by the current - * ->submit_bio. - * bio_list_on_stack[1] contains bios that were submitted before the - * current ->submit_bio_bio, but that haven't been processed yet. - */ - struct bio_list bio_list_on_stack[2]; - blk_qc_t ret = BLK_QC_T_NONE; - if (!submit_bio_checks(bio)) - goto out; + return BLK_QC_T_NONE; /* * We only want one ->submit_bio to be active at a time, else @@ -1120,58 +1179,10 @@ blk_qc_t submit_bio_noacct(struct bio *bio) */ if (current->bio_list) { bio_list_add(¤t->bio_list[0], bio); - goto out; + return BLK_QC_T_NONE; } - /* following loop may be a bit non-obvious, and so deserves some - * explanation. - * Before entering the loop, bio->bi_next is NULL (as all callers - * ensure that) so we have a list with a single bio. - * We pretend that we have just taken it off a longer list, so - * we assign bio_list to a pointer to the bio_list_on_stack, - * thus initialising the bio_list of new bios to be - * added. ->submit_bio() may indeed add some more bios - * through a recursive call to submit_bio_noacct. If it - * did, we find a non-NULL value in bio_list and re-enter the loop - * from the top. In this case we really did just take the bio - * of the top of the list (no pretending) and so remove it from - * bio_list, and call into ->submit_bio() again. - */ - BUG_ON(bio->bi_next); - bio_list_init(&bio_list_on_stack[0]); - current->bio_list = bio_list_on_stack; - do { - struct request_queue *q = bio->bi_disk->queue; - - if (likely(bio_queue_enter(bio) == 0)) { - struct bio_list lower, same; - - /* Create a fresh bio_list for all subordinate requests */ - bio_list_on_stack[1] = bio_list_on_stack[0]; - bio_list_init(&bio_list_on_stack[0]); - ret = do_make_request(bio); - - /* sort new bios into those for a lower level - * and those for the same level - */ - bio_list_init(&lower); - bio_list_init(&same); - while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) - if (q == bio->bi_disk->queue) - bio_list_add(&same, bio); - else - bio_list_add(&lower, bio); - /* now assemble so we handle the lowest level first */ - bio_list_merge(&bio_list_on_stack[0], &lower); - bio_list_merge(&bio_list_on_stack[0], &same); - bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); - } - bio = bio_list_pop(&bio_list_on_stack[0]); - } while (bio); - current->bio_list = NULL; /* deactivate */ - -out: - return ret; + return __submit_bio_noacct(bio); } EXPORT_SYMBOL(submit_bio_noacct);
Split out a __submit_bio_noacct helper for the actual de-recursion algorithm, and simplify the loop by using a continue when we can't enter the queue for a bio. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/blk-core.c | 131 +++++++++++++++++++++++++---------------------- 1 file changed, 71 insertions(+), 60 deletions(-)