kernel/linux.git/fs, branch linux-5.9.y

zonefs: fix page reference and BIO leak

2020-12-16T09:58:37+00:00

commit 6bea0225a4bf14a58af71cb9677a756921469e46 upstream. In zonefs_file_dio_append(), the pages obtained using bio_iov_iter_get_pages() are not released on completion of the REQ_OP_APPEND BIO, nor when bio_iov_iter_get_pages() fails. Furthermore, a call to bio_put() is missing when bio_iov_iter_get_pages() fails. Fix these resource leaks by adding BIO resource release code (bio_put()i and bio_release_pages()) at the end of the function after the BIO execution and add a jump to this resource cleanup code in case of bio_iov_iter_get_pages() failure. While at it, also fix the call to task_io_account_write() to be passed the correct BIO size instead of bio_iov_iter_get_pages() return value. Reported-by: Christoph Hellwig Fixes: 02ef12a663c7 ("zonefs: use REQ_OP_ZONE_APPEND for sync DIO") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman

proc: use untagged_addr() for pagemap_read addresses

2020-12-16T09:58:37+00:00

commit 40d6366e9d86d9a67b5642040e76082fdb5bdcf9 upstream. When we try to visit the pagemap of a tagged userspace pointer, we find that the start_vaddr is not correct because of the tag. To fix it, we should untag the userspace pointers in pagemap_read(). I tested with 5.10-rc4 and the issue remains. Explanation from Catalin in [1]: "Arguably, that's a user-space bug since tagged file offsets were never supported. In this case it's not even a tag at bit 56 as per the arm64 tagged address ABI but rather down to bit 47. You could say that the problem is caused by the C library (malloc()) or whoever created the tagged vaddr and passed it to this function. It's not a kernel regression as we've never supported it. Now, pagemap is a special case where the offset is usually not generated as a classic file offset but rather derived by shifting a user virtual address. I guess we can make a concession for pagemap (only) and allow such offset with the tag at bit (56 - PAGE_SHIFT + 3)" My test code is based on [2]: A userspace pointer which has been tagged by 0xb4: 0xb400007662f541c8 userspace program: uint64 OsLayer::VirtualToPhysical(void *vaddr) { uint64 frame, paddr, pfnmask, pagemask; int pagesize = sysconf(_SC_PAGESIZE); off64_t off = ((uintptr_t)vaddr) / pagesize * 8; // off = 0xb400007662f541c8 / pagesize * 8 = 0x5a00003b317aa0 int fd = open(kPagemapPath, O_RDONLY); ... if (lseek64(fd, off, SEEK_SET) != off || read(fd, &frame, 8) != 8) { int err = errno; string errtxt = ErrorString(err); if (fd >= 0) close(fd); return 0; } ... } kernel fs/proc/task_mmu.c: static ssize_t pagemap_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { ... src = *ppos; svpfn = src / PM_ENTRY_BYTES; // svpfn == 0xb400007662f54 start_vaddr = svpfn << PAGE_SHIFT; // start_vaddr == 0xb400007662f54000 end_vaddr = mm->task_size; /* watch out for wraparound */ // svpfn == 0xb400007662f54 // (mm->task_size >> PAGE) == 0x8000000 if (svpfn > mm->task_size >> PAGE_SHIFT) // the condition is true because of the tag 0xb4 start_vaddr = end_vaddr; ret = 0; while (count && (start_vaddr < end_vaddr)) { // we cannot visit correct entry because start_vaddr is set to end_vaddr int len; unsigned long end; ... } ... } [1] https://lore.kernel.org/patchwork/patch/1343258/ [2] https://github.com/stressapptest/stressapptest/blob/master/src/os.cc#L158 Link: https://lkml.kernel.org/r/20201204024347.8295-1-miles.chen@mediatek.com Signed-off-by: Miles Chen Reviewed-by: Vincenzo Frascino Reviewed-by: Catalin Marinas Cc: Alexey Dobriyan Cc: Andrey Konovalov Cc: Alexander Potapenko Cc: Vincenzo Frascino Cc: Andrey Ryabinin Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Marco Elver Cc: Will Deacon Cc: Eric W. Biederman Cc: Song Bao Hua (Barry Song) Cc: [5.4-] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

btrfs: fix lockdep splat when enabling and disabling qgroups

2020-12-16T09:58:32+00:00

[ Upstream commit a855fbe69229078cd8aecd8974fb996a5ca651e6 ] When running test case btrfs/017 from fstests, lockdep reported the following splat: [ 1297.067385] ====================================================== [ 1297.067708] WARNING: possible circular locking dependency detected [ 1297.068022] 5.10.0-rc4-btrfs-next-73 #1 Not tainted [ 1297.068322] ------------------------------------------------------ [ 1297.068629] btrfs/189080 is trying to acquire lock: [ 1297.068929] ffff9f2725731690 (sb_internal#2){.+.+}-{0:0}, at: btrfs_quota_enable+0xaf/0xa70 [btrfs] [ 1297.069274] but task is already holding lock: [ 1297.069868] ffff9f2702b61a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0xa70 [btrfs] [ 1297.070219] which lock already depends on the new lock. [ 1297.071131] the existing dependency chain (in reverse order) is: [ 1297.071721] -> #1 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}: [ 1297.072375] lock_acquire+0xd8/0x490 [ 1297.072710] __mutex_lock+0xa3/0xb30 [ 1297.073061] btrfs_qgroup_inherit+0x59/0x6a0 [btrfs] [ 1297.073421] create_subvol+0x194/0x990 [btrfs] [ 1297.073780] btrfs_mksubvol+0x3fb/0x4a0 [btrfs] [ 1297.074133] __btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs] [ 1297.074498] btrfs_ioctl_snap_create+0x58/0x80 [btrfs] [ 1297.074872] btrfs_ioctl+0x1a90/0x36f0 [btrfs] [ 1297.075245] __x64_sys_ioctl+0x83/0xb0 [ 1297.075617] do_syscall_64+0x33/0x80 [ 1297.075993] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1297.076380] -> #0 (sb_internal#2){.+.+}-{0:0}: [ 1297.077166] check_prev_add+0x91/0xc60 [ 1297.077572] __lock_acquire+0x1740/0x3110 [ 1297.077984] lock_acquire+0xd8/0x490 [ 1297.078411] start_transaction+0x3c5/0x760 [btrfs] [ 1297.078853] btrfs_quota_enable+0xaf/0xa70 [btrfs] [ 1297.079323] btrfs_ioctl+0x2c60/0x36f0 [btrfs] [ 1297.079789] __x64_sys_ioctl+0x83/0xb0 [ 1297.080232] do_syscall_64+0x33/0x80 [ 1297.080680] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1297.081139] other info that might help us debug this: [ 1297.082536] Possible unsafe locking scenario: [ 1297.083510] CPU0 CPU1 [ 1297.084005] ---- ---- [ 1297.084500] lock(&fs_info->qgroup_ioctl_lock); [ 1297.084994] lock(sb_internal#2); [ 1297.085485] lock(&fs_info->qgroup_ioctl_lock); [ 1297.085974] lock(sb_internal#2); [ 1297.086454] *** DEADLOCK *** [ 1297.087880] 3 locks held by btrfs/189080: [ 1297.088324] #0: ffff9f2725731470 (sb_writers#14){.+.+}-{0:0}, at: btrfs_ioctl+0xa73/0x36f0 [btrfs] [ 1297.088799] #1: ffff9f2702b60cc0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl+0x1f4d/0x36f0 [btrfs] [ 1297.089284] #2: ffff9f2702b61a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0xa70 [btrfs] [ 1297.089771] stack backtrace: [ 1297.090662] CPU: 5 PID: 189080 Comm: btrfs Not tainted 5.10.0-rc4-btrfs-next-73 #1 [ 1297.091132] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 1297.092123] Call Trace: [ 1297.092629] dump_stack+0x8d/0xb5 [ 1297.093115] check_noncircular+0xff/0x110 [ 1297.093596] check_prev_add+0x91/0xc60 [ 1297.094076] ? kvm_clock_read+0x14/0x30 [ 1297.094553] ? kvm_sched_clock_read+0x5/0x10 [ 1297.095029] __lock_acquire+0x1740/0x3110 [ 1297.095510] lock_acquire+0xd8/0x490 [ 1297.095993] ? btrfs_quota_enable+0xaf/0xa70 [btrfs] [ 1297.096476] start_transaction+0x3c5/0x760 [btrfs] [ 1297.096962] ? btrfs_quota_enable+0xaf/0xa70 [btrfs] [ 1297.097451] btrfs_quota_enable+0xaf/0xa70 [btrfs] [ 1297.097941] ? btrfs_ioctl+0x1f4d/0x36f0 [btrfs] [ 1297.098429] btrfs_ioctl+0x2c60/0x36f0 [btrfs] [ 1297.098904] ? do_user_addr_fault+0x20c/0x430 [ 1297.099382] ? kvm_clock_read+0x14/0x30 [ 1297.099854] ? kvm_sched_clock_read+0x5/0x10 [ 1297.100328] ? sched_clock+0x5/0x10 [ 1297.100801] ? sched_clock_cpu+0x12/0x180 [ 1297.101272] ? __x64_sys_ioctl+0x83/0xb0 [ 1297.101739] __x64_sys_ioctl+0x83/0xb0 [ 1297.102207] do_syscall_64+0x33/0x80 [ 1297.102673] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1297.103148] RIP: 0033:0x7f773ff65d87 This is because during the quota enable ioctl we lock first the mutex qgroup_ioctl_lock and then start a transaction, and starting a transaction acquires a fs freeze semaphore (at the VFS level). However, every other code path, except for the quota disable ioctl path, we do the opposite: we start a transaction and then lock the mutex. So fix this by making the quota enable and disable paths to start the transaction without having the mutex locked, and then, after starting the transaction, lock the mutex and check if some other task already enabled or disabled the quotas, bailing with success if that was the case. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: do nofs allocations when adding and removing qgroup relations

2020-12-16T09:58:32+00:00

[ Upstream commit 7aa6d359845a9dbf7ad90b0b1b6347ef4764621f ] When adding or removing a qgroup relation we are doing a GFP_KERNEL allocation which is not safe because we are holding a transaction handle open and that can make us deadlock if the allocator needs to recurse into the filesystem. So just surround those calls with a nofs context. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

gfs2: Don't freeze the file system during unmount

2020-12-11T12:22:12+00:00

commit f39e7d3aae2934b1cfdd209b54c508e2552e9531 upstream. GFS2's freeze/thaw mechanism uses a special freeze glock to control its operation. It does this with a sync glock operation (glops.c) called freeze_go_sync. When the freeze glock is demoted (glock's do_xmote) the glops function causes the file system to be frozen. This is intended. However, GFS2's mount and unmount processes also hold the freeze glock to prevent other processes, perhaps on different cluster nodes, from mounting the frozen file system in read-write mode. Before this patch, there was no check in freeze_go_sync for whether a freeze in intended or whether the glock demote was caused by a normal unmount. So it was trying to freeze the file system it's trying to unmount, which ends up in a deadlock. This patch adds an additional check to freeze_go_sync so that demotes of the freeze glock are ignored if they come from the unmount process. Fixes: 20b329129009 ("gfs2: Fix regression in freeze_go_sync") Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: Fix deadlock dumping resource group glocks

2020-12-11T12:22:12+00:00

commit 16e6281b6b22b0178eab95c6a82502d7b10f67b8 upstream. Commit 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump") introduced additional locking in gfs2_rgrp_go_dump, which is also used for dumping resource group glocks via debugfs. However, on that code path, the glock spin lock is already taken in dump_glock, and taking it again in gfs2_glock2rgrp leads to deadlock. This can be reproduced with: $ mkfs.gfs2 -O -p lock_nolock /dev/FOO $ mount /dev/FOO /mnt/foo $ touch /mnt/foo/bar $ cat /sys/kernel/debug/gfs2/FOO/glocks Fix that by not taking the glock spin lock inside the go_dump callback. Fixes: 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump") Signed-off-by: Alexander Aring Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: check for empty rgrp tree in gfs2_ri_update

2020-12-11T12:22:11+00:00

commit 778721510e84209f78e31e2ccb296ae36d623f5e upstream. If gfs2 tries to mount a (corrupt) file system that has no resource groups it still tries to set preferences on the first one, which causes a kernel null pointer dereference. This patch adds a check to function gfs2_ri_update so this condition is detected and reported back as an error. Reported-by: syzbot+e3f23ce40269a4c9053a@syzkaller.appspotmail.com Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

coredump: fix core_pattern parse error

2020-12-11T12:22:10+00:00

commit 2bf509d96d84c3336d08375e8af34d1b85ee71c8 upstream. 'format_corename()' will splite 'core_pattern' on spaces when it is in pipe mode, and take helper_argv[0] as the path to usermode executable. It works fine in most cases. However, if there is a space between '|' and '/file/path', such as '| /usr/lib/systemd/systemd-coredump %P %u %g', then helper_argv[0] will be parsed as '', and users will get a 'Core dump to | disabled'. It is not friendly to users, as the pattern above was valid previously. Fix this by ignoring the spaces between '|' and '/file/path'. Fixes: 315c69261dd3 ("coredump: split pipe command whitespace before expanding template") Signed-off-by: Menglong Dong Signed-off-by: Andrew Morton Cc: Paul Wise Cc: Jakub Wilk [https://bugs.debian.org/924398] Cc: Neil Horman Cc: Link: https://lkml.kernel.org/r/5fb62870.1c69fb81.8ef5d.af76@mx.google.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

io_uring: fix recvmsg setup with compat buf-select

2020-12-11T12:22:09+00:00

commit 2d280bc8930ba9ed1705cfd548c6c8924949eaf1 upstream. __io_compat_recvmsg_copy_hdr() with REQ_F_BUFFER_SELECT reads out iov len but never assigns it to iov/fast_iov, leaving sr->len with garbage. Hopefully, following io_buffer_select() truncates it to the selected buffer size, but the value is still may be under what was specified. Cc: # 5.7 Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

gfs2: Fix deadlock between gfs2_{create_inode,inode_lookup} and delete_work_func

2020-12-11T12:22:07+00:00

commit dd0ecf544125639e54056d851e4887dbb94b6d2f upstream. In gfs2_create_inode and gfs2_inode_lookup, make sure to cancel any pending delete work before taking the inode glock. Otherwise, gfs2_cancel_delete_work may block waiting for delete_work_func to complete, and delete_work_func may block trying to acquire the inode glock in gfs2_inode_lookup. Reported-by: Alexander Aring Fixes: a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman