user/sven/linux.git/fs, branch v4.20.5

userfaultfd: clear flag if remap event not enabled

2019-01-26T08:20:51Z

[ Upstream commit 3cfd22be0ad663248fadfc8f6ffa3e255c394552 ] When the process being tracked does mremap() without UFFD_FEATURE_EVENT_REMAP on the corresponding tracking uffd file handle, we should not generate the remap event, and at the same time we should clear all the uffd flags on the new VMA. Without this patch, we can still have the VM_UFFD_MISSING|VM_UFFD_WP flags on the new VMA even the fault handling process does not even know the existance of the VMA. Link: http://lkml.kernel.org/r/20181211053409.20317-1-peterx@redhat.com Signed-off-by: Peter Xu Reviewed-by: Andrea Arcangeli Acked-by: Mike Rapoport Reviewed-by: William Kucharski Cc: Andrea Arcangeli Cc: Mike Rapoport Cc: Kirill A. Shutemov Cc: Hugh Dickins Cc: Pavel Emelyanov Cc: Pravin Shedge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

ocfs2: fix panic due to unrecovered local alloc

2019-01-26T08:20:50Z

[ Upstream commit 532e1e54c8140188e192348c790317921cb2dc1c ] mount.ocfs2 ignore the inconsistent error that journal is clean but local alloc is unrecovered. After mount, local alloc not empty, then reserver cluster didn't alloc a new local alloc window, reserveration map is empty(ocfs2_reservation_map.m_bitmap_len = 0), that triggered the following panic. This issue was reported at https://oss.oracle.com/pipermail/ocfs2-devel/2015-May/010854.html and was advised to fixed during mount. But this is a very unusual inconsistent state, usually journal dirty flag should be cleared at the last stage of umount until every other things go right. We may need do further debug to check that. Any way to avoid possible futher corruption, mount should be abort and fsck should be run. (mount.ocfs2,1765,1):ocfs2_load_local_alloc:353 ERROR: Local alloc hasn't been recovered! found = 6518, set = 6518, taken = 8192, off = 15912372 ocfs2: Mounting device (202,64) on (node 0, slot 3) with ordered data mode. o2dlm: Joining domain 89CEAC63CC4F4D03AC185B44E0EE0F3F ( 0 1 2 3 4 5 6 8 ) 8 nodes ocfs2: Mounting device (202,80) on (node 0, slot 3) with ordered data mode. o2hb: Region 89CEAC63CC4F4D03AC185B44E0EE0F3F (xvdf) is now a quorum device o2net: Accepted connection from node yvwsoa17p (num 7) at 172.22.77.88:7777 o2dlm: Node 7 joins domain 64FE421C8C984E6D96ED12C55FEE2435 ( 0 1 2 3 4 5 6 7 8 ) 9 nodes o2dlm: Node 7 joins domain 89CEAC63CC4F4D03AC185B44E0EE0F3F ( 0 1 2 3 4 5 6 7 8 ) 9 nodes ------------[ cut here ]------------ kernel BUG at fs/ocfs2/reservations.c:507! invalid opcode: 0000 [#1] SMP Modules linked in: ocfs2 rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs fscache lockd grace ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sunrpc ipt_REJECT nf_reject_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 ovmapi ppdev parport_pc parport xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea acpi_cpufreq pcspkr i2c_piix4 i2c_core sg ext4 jbd2 mbcache2 sr_mod cdrom xen_blkfront pata_acpi ata_generic ata_piix floppy dm_mirror dm_region_hash dm_log dm_mod CPU: 0 PID: 4349 Comm: startWebLogic.s Not tainted 4.1.12-124.19.2.el6uek.x86_64 #2 Hardware name: Xen HVM domU, BIOS 4.4.4OVM 09/06/2018 task: ffff8803fb04e200 ti: ffff8800ea4d8000 task.ti: ffff8800ea4d8000 RIP: 0010:[] [] __ocfs2_resv_find_window+0x498/0x760 [ocfs2] Call Trace: ocfs2_resmap_resv_bits+0x10d/0x400 [ocfs2] ocfs2_claim_local_alloc_bits+0xd0/0x640 [ocfs2] __ocfs2_claim_clusters+0x178/0x360 [ocfs2] ocfs2_claim_clusters+0x1f/0x30 [ocfs2] ocfs2_convert_inline_data_to_extents+0x634/0xa60 [ocfs2] ocfs2_write_begin_nolock+0x1c6/0x1da0 [ocfs2] ocfs2_write_begin+0x13e/0x230 [ocfs2] generic_perform_write+0xbf/0x1c0 __generic_file_write_iter+0x19c/0x1d0 ocfs2_file_write_iter+0x589/0x1360 [ocfs2] __vfs_write+0xb8/0x110 vfs_write+0xa9/0x1b0 SyS_write+0x46/0xb0 system_call_fastpath+0x18/0xd7 Code: ff ff 8b 75 b8 39 75 b0 8b 45 c8 89 45 98 0f 84 e5 fe ff ff 45 8b 74 24 18 41 8b 54 24 1c e9 56 fc ff ff 85 c0 0f 85 48 ff ff ff <0f> 0b 48 8b 05 cf c3 de ff 48 ba 00 00 00 00 00 00 00 10 48 85 RIP __ocfs2_resv_find_window+0x498/0x760 [ocfs2] RSP ---[ end trace 566f07529f2edf3c ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled Link: http://lkml.kernel.org/r/20181121020023.3034-2-junxiao.bi@oracle.com Signed-off-by: Junxiao Bi Reviewed-by: Yiwen Jiang Acked-by: Joseph Qi Cc: Jun Piao Cc: Mark Fasheh Cc: Joel Becker Cc: Changwei Ge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

iomap: don't search past page end in iomap_is_partially_uptodate

2019-01-26T08:20:50Z

[ Upstream commit 3cc31fa65d85610574c0f6a474e89f4c419923d5 ] iomap_is_partially_uptodate() is intended to check wither blocks within the selected range of a not-uptodate page are uptodate; if the range we care about is up to date, it's an optimization. However, the iomap implementation continues to check all blocks up to from+count, which is beyond the page, and can even be well beyond the iop->uptodate bitmap. I think the worst that will happen is that we may eventually find a zero bit and return "not partially uptodate" when it would have otherwise returned true, and skip the optimization. Still, it's clearly an invalid memory access that must be fixed. So: fix this by limiting the search to within the page as is done in the non-iomap variant, block_is_partially_uptodate(). Zorro noticed thiswhen KASAN went off for 512 byte blocks on a 64k page system: BUG: KASAN: slab-out-of-bounds in iomap_is_partially_uptodate+0x1a0/0x1e0 Read of size 8 at addr ffff800120c3a318 by task fsstress/22337 Reported-by: Zorro Lang Signed-off-by: Eric Sandeen Signed-off-by: Eric Sandeen Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin

quota: Lock s_umount in exclusive mode for Q_XQUOTA{ON,OFF} quotactls.

2019-01-26T08:20:49Z

[ Upstream commit 41c4f85cdac280d356df1f483000ecec4a8868be ] Commit 1fa5efe3622db58cb8c7b9a50665e9eb9a6c7e97 (ext4: Use generic helpers for quotaon and quotaoff) made possible to call quotactl(Q_XQUOTAON/OFF) on ext4 filesystems with sysfile quota support. This leads to calling dquot_enable/disable without s_umount held in excl. mode, because quotactl_cmd_onoff checks only for Q_QUOTAON/OFF. The following WARN_ON_ONCE triggers (in this case for dquot_enable, ext4, latest Linus' tree): [ 117.807056] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: quota,prjquota [...] [ 155.036847] WARNING: CPU: 0 PID: 2343 at fs/quota/dquot.c:2469 dquot_enable+0x34/0xb9 [ 155.036851] Modules linked in: quota_v2 quota_tree ipv6 af_packet joydev mousedev psmouse serio_raw pcspkr i2c_piix4 intel_agp intel_gtt e1000 ttm drm_kms_helper drm agpgart fb_sys_fops syscopyarea sysfillrect sysimgblt i2c_core input_leds kvm_intel kvm irqbypass qemu_fw_cfg floppy evdev parport_pc parport button crc32c_generic dm_mod ata_generic pata_acpi ata_piix libata loop ext4 crc16 mbcache jbd2 usb_storage usbcore sd_mod scsi_mod [ 155.036901] CPU: 0 PID: 2343 Comm: qctl Not tainted 4.20.0-rc6-00025-gf5d582777bcb #9 [ 155.036903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 155.036911] RIP: 0010:dquot_enable+0x34/0xb9 [ 155.036915] Code: 41 56 41 55 41 54 55 53 4c 8b 6f 28 74 02 0f 0b 4d 8d 7d 70 49 89 fc 89 cb 41 89 d6 89 f5 4c 89 ff e8 23 09 ea ff 85 c0 74 0a <0f> 0b 4c 89 ff e8 8b 09 ea ff 85 db 74 6a 41 8b b5 f8 00 00 00 0f [ 155.036918] RSP: 0018:ffffb09b00493e08 EFLAGS: 00010202 [ 155.036922] RAX: 0000000000000001 RBX: 0000000000000008 RCX: 0000000000000008 [ 155.036924] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9781b67cd870 [ 155.036926] RBP: 0000000000000002 R08: 0000000000000000 R09: 61c8864680b583eb [ 155.036929] R10: ffffb09b00493e48 R11: ffffffffff7ce7d4 R12: ffff9781b7ee8d78 [ 155.036932] R13: ffff9781b67cd800 R14: 0000000000000004 R15: ffff9781b67cd870 [ 155.036936] FS: 00007fd813250b88(0000) GS:ffff9781ba000000(0000) knlGS:0000000000000000 [ 155.036939] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 155.036942] CR2: 00007fd812ff61d6 CR3: 000000007c882000 CR4: 00000000000006b0 [ 155.036951] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 155.036953] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 155.036955] Call Trace: [ 155.037004] dquot_quota_enable+0x8b/0xd0 [ 155.037011] kernel_quotactl+0x628/0x74e [ 155.037027] ? do_mprotect_pkey+0x2a6/0x2cd [ 155.037034] __x64_sys_quotactl+0x1a/0x1d [ 155.037041] do_syscall_64+0x55/0xe4 [ 155.037078] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 155.037105] RIP: 0033:0x7fd812fe1198 [ 155.037109] Code: 02 77 0d 48 89 c1 48 c1 e9 3f 75 04 48 8b 04 24 48 83 c4 50 5b c3 48 83 ec 08 49 89 ca 48 63 d2 48 63 ff b8 b3 00 00 00 0f 05 <48> 89 c7 e8 c1 eb ff ff 5a c3 48 63 ff b8 bb 00 00 00 0f 05 48 89 [ 155.037112] RSP: 002b:00007ffe8cd7b050 EFLAGS: 00000206 ORIG_RAX: 00000000000000b3 [ 155.037116] RAX: ffffffffffffffda RBX: 00007ffe8cd7b148 RCX: 00007fd812fe1198 [ 155.037119] RDX: 0000000000000000 RSI: 00007ffe8cd7cea9 RDI: 0000000000580102 [ 155.037121] RBP: 00007ffe8cd7b0f0 R08: 000055fc8eba8a9d R09: 0000000000000000 [ 155.037124] R10: 00007ffe8cd7b074 R11: 0000000000000206 R12: 00007ffe8cd7b168 [ 155.037126] R13: 000055fc8eba8897 R14: 0000000000000000 R15: 0000000000000000 [ 155.037131] ---[ end trace 210f864257175c51 ]--- and then the syscall proceeds without s_umount locking. This patch locks the superblock ->s_umount sem. in exclusive mode for all Q_XQUOTAON/OFF quotactls too in addition to Q_QUOTAON/OFF. AFAICT, other than ext4, only xfs and ocfs2 are affected by this change. The VFS will now call in xfs_quota_* functions with s_umount held, which wasn't the case before. This looks good to me but I can not say for sure. Ext4 and ocfs2 where already beeing called with s_umount exclusive via quota_quotaon/off which is basically the same. Signed-off-by: Javier Barrio Signed-off-by: Jan Kara Signed-off-by: Sasha Levin

btrfs: improve error handling of btrfs_add_link

2019-01-26T08:20:46Z

[ Upstream commit 1690dd41e0cb1dade80850ed8a3eb0121b96d22f ] In the error handling block, err holds the return value of either btrfs_del_root_ref() or btrfs_del_inode_ref() but it hasn't been checked since it's introduction with commit fe66a05a0679 (Btrfs: improve error handling for btrfs_insert_dir_item callers) in 2012. If the error handling in the error handling fails, there's not much left to do and the abort either happened earlier in the callees or is necessary here. So if one of btrfs_del_root_ref() or btrfs_del_inode_ref() failed, abort the transaction, but still return the original code of the failure stored in 'ret' as this will be reported to the user. Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: fix use-after-free due to race between replace start and cancel

2019-01-26T08:20:46Z

[ Upstream commit d189dd70e2556181732598956d808ea53cc8774e ] The device replace cancel thread can race with the replace start thread and if fs_info::scrubs_running is not yet set, btrfs_scrub_cancel() will fail to stop the scrub thread. The scrub thread continues with the scrub for replace which then will try to write to the target device and which is already freed by the cancel thread. scrub_setup_ctx() warns as tgtdev is NULL. struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace) { ... if (is_dev_replace) { WARN_ON(!fs_info->dev_replace.tgtdev); <=== sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO; sctx->wr_tgtdev = fs_info->dev_replace.tgtdev; sctx->flush_all_writes = false; } [ 6724.497655] BTRFS info (device sdb): dev_replace from /dev/sdb (devid 1) to /dev/sdc started [ 6753.945017] BTRFS info (device sdb): dev_replace from /dev/sdb (devid 1) to /dev/sdc canceled [ 6852.426700] WARNING: CPU: 0 PID: 4494 at fs/btrfs/scrub.c:622 scrub_setup_ctx.isra.19+0x220/0x230 [btrfs] ... [ 6852.428928] RIP: 0010:scrub_setup_ctx.isra.19+0x220/0x230 [btrfs] ... [ 6852.432970] Call Trace: [ 6852.433202] btrfs_scrub_dev+0x19b/0x5c0 [btrfs] [ 6852.433471] btrfs_dev_replace_start+0x48c/0x6a0 [btrfs] [ 6852.433800] btrfs_dev_replace_by_ioctl+0x3a/0x60 [btrfs] [ 6852.434097] btrfs_ioctl+0x2476/0x2d20 [btrfs] [ 6852.434365] ? do_sigaction+0x7d/0x1e0 [ 6852.434623] do_vfs_ioctl+0xa9/0x6c0 [ 6852.434865] ? syscall_trace_enter+0x1c8/0x310 [ 6852.435124] ? syscall_trace_enter+0x1c8/0x310 [ 6852.435387] ksys_ioctl+0x60/0x90 [ 6852.435663] __x64_sys_ioctl+0x16/0x20 [ 6852.435907] do_syscall_64+0x50/0x180 [ 6852.436150] entry_SYSCALL_64_after_hwframe+0x49/0xbe Further, as the replace thread enters scrub_write_page_to_dev_replace() without the target device it panics: static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx, struct scrub_page *spage) { ... bio_set_dev(bio, sbio->dev->bdev); <====== [ 6929.715145] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0 .. [ 6929.717106] Workqueue: btrfs-scrub btrfs_scrub_helper [btrfs] [ 6929.717420] RIP: 0010:scrub_write_page_to_dev_replace+0xb4/0x260 [btrfs] .. [ 6929.721430] Call Trace: [ 6929.721663] scrub_write_block_to_dev_replace+0x3f/0x60 [btrfs] [ 6929.721975] scrub_bio_end_io_worker+0x1af/0x490 [btrfs] [ 6929.722277] normal_work_helper+0xf0/0x4c0 [btrfs] [ 6929.722552] process_one_work+0x1f4/0x520 [ 6929.722805] ? process_one_work+0x16e/0x520 [ 6929.723063] worker_thread+0x46/0x3d0 [ 6929.723313] kthread+0xf8/0x130 [ 6929.723544] ? process_one_work+0x520/0x520 [ 6929.723800] ? kthread_delayed_work_timer_fn+0x80/0x80 [ 6929.724081] ret_from_fork+0x3a/0x50 Fix this by letting the btrfs_dev_replace_finishing() to do the job of cleaning after the cancel, including freeing of the target device. btrfs_dev_replace_finishing() is called when btrfs_scub_dev() returns along with the scrub return status. Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: alloc_chunk: fix more DUP stripe size handling

2019-01-26T08:20:46Z

[ Upstream commit baf92114c7e6dd6124aa3d506e4bc4b694da3bc3 ] Commit 92e222df7b "btrfs: alloc_chunk: fix DUP stripe size handling" fixed calculating the stripe_size for a new DUP chunk. However, the same calculation reappears a bit later, and that one was not changed yet. The resulting bug that is exposed is that the newly allocated device extents ('stripes') can have a few MiB overlap with the next thing stored after them, which is another device extent or the end of the disk. The scenario in which this can happen is: * The block device for the filesystem is less than 10GiB in size. * The amount of contiguous free unallocated disk space chosen to use for chunk allocation is 20% of the total device size, or a few MiB more or less. An example: - The filesystem device is 7880MiB (max_chunk_size gets set to 788MiB) - There's 1578MiB unallocated raw disk space left in one contiguous piece. In this case stripe_size is first calculated as 789MiB, (half of 1578MiB). Since 789MiB (stripe_size * data_stripes) > 788MiB (max_chunk_size), we enter the if block. Now stripe_size value is immediately overwritten while calculating an adjusted value based on max_chunk_size, which ends up as 788MiB. Next, the value is rounded up to a 16MiB boundary, 800MiB, which is actually more than the value we had before. However, the last comparison fails to detect this, because it's comparing the value with the total amount of free space, which is about twice the size of stripe_size. In the example above, this means that the resulting raw disk space being allocated is 1600MiB, while only a gap of 1578MiB has been found. The second device extent object for this DUP chunk will overlap for 22MiB with whatever comes next. The underlying problem here is that the stripe_size is reused all the time for different things. So, when entering the code in the if block, stripe_size is immediately overwritten with something else. If later we decide we want to have the previous value back, then the logic to compute it was copy pasted in again. With this change, the value in stripe_size is not unnecessarily destroyed, so the duplicated calculation is not needed any more. Signed-off-by: Hans van Kranenburg Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: volumes: Make sure there is no overlap of dev extents at mount time

2019-01-26T08:20:46Z

[ Upstream commit 5eb193812a42dc49331f25137a38dfef9612d3e4 ] Enhance btrfs_verify_dev_extents() to remember previous checked dev extents, so it can verify no dev extents can overlap. Analysis from Hans: "Imagine allocating a DATA|DUP chunk. In the chunk allocator, we first set... max_stripe_size = SZ_1G; max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE ... which is 10GiB. Then... /* we don't want a chunk larger than 10% of writeable space */ max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1), max_chunk_size); Imagine we only have one 7880MiB block device in this filesystem. Now max_chunk_size is down to 788MiB. The next step in the code is to search for max_stripe_size * dev_stripes amount of free space on the device, which is in our example 1GiB * 2 = 2GiB. Imagine the device has exactly 1578MiB free in one contiguous piece. This amount of bytes will be put in devices_info[ndevs - 1].max_avail Next we recalculate the stripe_size (which is actually the device extent length), based on the actual maximum amount of available raw disk space: stripe_size = div_u64(devices_info[ndevs - 1].max_avail, dev_stripes); stripe_size is now 789MiB Next we do... data_stripes = num_stripes / ncopies ...where data_stripes ends up as 1, because num_stripes is 2 (the amount of device extents we're going to have), and DUP has ncopies 2. Next there's a check... if (stripe_size * data_stripes > max_chunk_size) ...which matches because 789MiB * 1 > 788MiB. We go into the if code, and next is... stripe_size = div_u64(max_chunk_size, data_stripes); ...which resets stripe_size to max_chunk_size: 788MiB Next is a fun one... /* bump the answer up to a 16MB boundary */ stripe_size = round_up(stripe_size, SZ_16M); ...which changes stripe_size from 788MiB to 800MiB. We're not done changing stripe_size yet... /* But don't go higher than the limits we found while searching * for free extents */ stripe_size = min(devices_info[ndevs - 1].max_avail, stripe_size); This is bad. max_avail is twice the stripe_size (we need to fit 2 device extents on the same device for DUP). The result here is that 800MiB < 1578MiB, so it's unchanged. However, the resulting DUP chunk will need 1600MiB disk space, which isn't there, and the second dev_extent might extend into the next thing (next dev_extent? end of device?) for 22MiB. The last shown line of code relies on a situation where there's twice the value of stripe_size present as value for the variable stripe_size when it's DUP. This was actually the case before commit 92e222df7b "btrfs: alloc_chunk: fix DUP stripe size handling", from which I quote: "[...] in the meantime there's a check to see if the stripe_size does not exceed max_chunk_size. Since during this check stripe_size is twice the amount as intended, the check will reduce the stripe_size to max_chunk_size if the actual correct to be used stripe_size is more than half the amount of max_chunk_size." In the previous version of the code, the 16MiB alignment (why is this done, by the way?) would result in a 50% chance that it would actually do an 8MiB alignment for the individual dev_extents, since it was operating on double the size. Does this matter? Does it matter that stripe_size can be set to anything which is not 16MiB aligned because of the amount of remaining available disk space which is just taken? What is the main purpose of this round_up? The most straightforward thing to do seems something like... stripe_size = min( div_u64(devices_info[ndevs - 1].max_avail, dev_stripes), stripe_size ) ..just putting half of the max_avail into stripe_size." Link: https://lore.kernel.org/linux-btrfs/b3461a38-e5f8-f41d-c67c-2efac8129054@mendix.com/ Reported-by: Hans van Kranenburg Signed-off-by: Qu Wenruo [ add analysis from report ] Signed-off-by: David Sterba Signed-off-by: Sasha Levin

pstore/ram: Do not treat empty buffers as valid

2019-01-26T08:20:43Z

[ Upstream commit 30696378f68a9e3dad6bfe55938b112e72af00c2 ] The ramoops backend currently calls persistent_ram_save_old() even if a buffer is empty. While this appears to work, it is does not seem like the right thing to do and could lead to future bugs so lets avoid that. It also prevents misleading prints in the logs which claim the buffer is valid. I got something like: found existing buffer, size 0, start 0 When I was expecting: no valid data in buffer (sig = ...) This bails out early (and reports with pr_debug()), since it's an acceptable state. Signed-off-by: Joel Fernandes (Google) Co-developed-by: Kees Cook Signed-off-by: Kees Cook Signed-off-by: Sasha Levin

jffs2: Fix use of uninitialized delayed_work, lockdep breakage

2019-01-26T08:20:43Z

[ Upstream commit a788c5272769ddbcdbab297cf386413eeac04463 ] jffs2_sync_fs makes the assumption that if CONFIG_JFFS2_FS_WRITEBUFFER is defined then a write buffer is available and has been initialized. However, this does is not the case when the mtd device has no out-of-band buffer: int jffs2_nand_flash_setup(struct jffs2_sb_info *c) { if (!c->mtd->oobsize) return 0; ... The resulting call to cancel_delayed_work_sync passing a uninitialized (but zeroed) delayed_work struct forces lockdep to become disabled. [ 90.050639] overlayfs: upper fs does not support tmpfile. [ 90.652264] INFO: trying to register non-static key. [ 90.662171] the code is fine but needs lockdep annotation. [ 90.673090] turning off the locking correctness validator. [ 90.684021] CPU: 0 PID: 1762 Comm: mount_root Not tainted 4.14.63 #0 [ 90.696672] Stack : 00000000 00000000 80d8f6a2 00000038 805f0000 80444600 8fe364f4 805dfbe7 [ 90.713349] 80563a30 000006e2 8068370c 00000001 00000000 00000001 8e2fdc48 ffffffff [ 90.730020] 00000000 00000000 80d90000 00000000 00000106 00000000 6465746e 312e3420 [ 90.746690] 6b636f6c 03bf0000 f8000000 20676e69 00000000 80000000 00000000 8e2c2a90 [ 90.763362] 80d90000 00000001 00000000 8e2c2a90 00000003 80260dc0 08052098 80680000 [ 90.780033] ... [ 90.784902] Call Trace: [ 90.789793] [<8000f0d8>] show_stack+0xb8/0x148 [ 90.798659] [<8005a000>] register_lock_class+0x270/0x55c [ 90.809247] [<8005cb64>] __lock_acquire+0x13c/0xf7c [ 90.818964] [<8005e314>] lock_acquire+0x194/0x1dc [ 90.828345] [<8003f27c>] flush_work+0x200/0x24c [ 90.837374] [<80041dfc>] __cancel_work_timer+0x158/0x210 [ 90.847958] [<801a8770>] jffs2_sync_fs+0x20/0x54 [ 90.857173] [<80125cf4>] iterate_supers+0xf4/0x120 [ 90.866729] [<80158fc4>] sys_sync+0x44/0x9c [ 90.875067] [<80014424>] syscall_common+0x34/0x58 Signed-off-by: Daniel Santos Reviewed-by: Hou Tao Signed-off-by: Boris Brezillon Signed-off-by: Sasha Levin