linux-stable.git/fs, branch v5.5.2 Linux kernel stable tree btrfs: do not zero f_bavail if we have available space 2020-02-04T18:18:03+00:00 Josef Bacik josef@toxicpanda.com 2020-01-31T14:31:05+00:00 165387a9c90152f35976d82feca6eff5f0d5ac02 commit d55966c4279bfc6a0cf0b32bf13f5df228a1eeb6 upstream. There was some logic added a while ago to clear out f_bavail in statfs() if we did not have enough free metadata space to satisfy our global reserve. This was incorrect at the time, however didn't really pose a problem for normal file systems because we would often allocate chunks if we got this low on free metadata space, and thus wouldn't really hit this case unless we were actually full. Fast forward to today and now we are much better about not allocating metadata chunks all of the time. Couple this with d792b0f19711 ("btrfs: always reserve our entire size for the global reserve") which now means we'll easily have a larger global reserve than our free space, we are now more likely to trip over this while still having plenty of space. Fix this by skipping this logic if the global rsv's space_info is not full. space_info->full is 0 unless we've attempted to allocate a chunk for that space_info and that has failed. If this happens then the space for the global reserve is definitely sacred and we need to report b_avail == 0, but before then we can just use our calculated b_avail. Reported-by: Martin Steigerwald <martin@lichtvoll.de> Fixes: ca8a51b3a979 ("btrfs: statfs: report zero available if metadata are exhausted") CC: stable@vger.kernel.org # 4.5+ Reviewed-by: Qu Wenruo <wqu@suse.com> Tested-By: Martin Steigerwald <martin@lichtvoll.de> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d55966c4279bfc6a0cf0b32bf13f5df228a1eeb6 upstream.

There was some logic added a while ago to clear out f_bavail in statfs()
if we did not have enough free metadata space to satisfy our global
reserve.  This was incorrect at the time, however didn't really pose a
problem for normal file systems because we would often allocate chunks
if we got this low on free metadata space, and thus wouldn't really hit
this case unless we were actually full.

Fast forward to today and now we are much better about not allocating
metadata chunks all of the time.  Couple this with d792b0f19711 ("btrfs:
always reserve our entire size for the global reserve") which now means
we'll easily have a larger global reserve than our free space, we are
now more likely to trip over this while still having plenty of space.

Fix this by skipping this logic if the global rsv's space_info is not
full.  space_info->full is 0 unless we've attempted to allocate a chunk
for that space_info and that has failed.  If this happens then the space
for the global reserve is definitely sacred and we need to report
b_avail == 0, but before then we can just use our calculated b_avail.

Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Fixes: ca8a51b3a979 ("btrfs: statfs: report zero available if metadata are exhausted")
CC: stable@vger.kernel.org # 4.5+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-By: Martin Steigerwald <martin@lichtvoll.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
reiserfs: Fix memory leak of journal device string 2020-02-04T18:18:02+00:00 Jan Kara jack@suse.cz 2019-12-12T10:30:03+00:00 8f5561c734b36c0b3089cbb381d8eecbe75ef72c commit 5474ca7da6f34fa95e82edc747d5faa19cbdfb5c upstream. When a filesystem is mounted with jdev mount option, we store the journal device name in an allocated string in superblock. However we fail to ever free that string. Fix it. Reported-by: syzbot+1c6756baf4b16b94d2a6@syzkaller.appspotmail.com Fixes: c3aa077648e1 ("reiserfs: Properly display mount options in /proc/mounts") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5474ca7da6f34fa95e82edc747d5faa19cbdfb5c upstream.

When a filesystem is mounted with jdev mount option, we store the
journal device name in an allocated string in superblock. However we
fail to ever free that string. Fix it.

Reported-by: syzbot+1c6756baf4b16b94d2a6@syzkaller.appspotmail.com
Fixes: c3aa077648e1 ("reiserfs: Properly display mount options in /proc/mounts")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gfs2: Another gfs2_find_jhead fix 2020-02-04T18:18:01+00:00 Andreas Gruenbacher agruenba@redhat.com 2019-12-08T13:12:49+00:00 917c9c80663a1aa4ea5e9703c73641256c1d2488 commit eed0f953b90e86e765197a1dad06bb48aedc27fe upstream. On filesystems with a block size smaller than the page size, gfs2_find_jhead can split a page across two bios (for example, when blocks are not allocated consecutively). When that happens, the first bio that completes will unlock the page in its bi_end_io handler even though the page hasn't been read completely yet. Fix that by using a chained bio for the rest of the page. While at it, clean up the sector calculation logic in gfs2_log_alloc_bio. In gfs2_find_jhead, simplify the disk block and offset calculation logic and fix a variable name. Fixes: f4686c26ecc3 ("gfs2: read journal in large chunks") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit eed0f953b90e86e765197a1dad06bb48aedc27fe upstream.

On filesystems with a block size smaller than the page size,
gfs2_find_jhead can split a page across two bios (for example, when
blocks are not allocated consecutively).  When that happens, the first
bio that completes will unlock the page in its bi_end_io handler even
though the page hasn't been read completely yet.  Fix that by using a
chained bio for the rest of the page.

While at it, clean up the sector calculation logic in
gfs2_log_alloc_bio.  In gfs2_find_jhead, simplify the disk block and
offset calculation logic and fix a variable name.

Fixes: f4686c26ecc3 ("gfs2: read journal in large chunks")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: fix soft mounts hanging in the reconnect code 2020-02-04T18:18:00+00:00 Ronnie Sahlberg lsahlber@redhat.com 2020-01-30T19:52:51+00:00 b9bbd35c4ca93de6aa649b46e02e95e425c9fdd3 commit c54849ddd832ae0a45cab16bcd1ed2db7da090d7 upstream. RHBZ: 1795429 In recent DFS updates we have a new variable controlling how many times we will retry to reconnect the share. If DFS is not used, then this variable is initialized to 0 in: static inline int dfs_cache_get_nr_tgts(const struct dfs_cache_tgt_list *tl) { return tl ? tl->tl_numtgts : 0; } This means that in the reconnect loop in smb2_reconnect() we will immediately wrap retries to -1 and never actually get to pass this conditional: if (--retries) continue; The effect is that we no longer reach the point where we fail the commands with -EHOSTDOWN and basically the kernel threads are virtually hung and unkillable. Fixes: a3a53b7603798fd8 (cifs: Add support for failover in smb2_reconnect()) Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> CC: Stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c54849ddd832ae0a45cab16bcd1ed2db7da090d7 upstream.

RHBZ: 1795429

In recent DFS updates we have a new variable controlling how many times we will
retry to reconnect the share.
If DFS is not used, then this variable is initialized to 0 in:

static inline int
dfs_cache_get_nr_tgts(const struct dfs_cache_tgt_list *tl)
{
        return tl ? tl->tl_numtgts : 0;
}

This means that in the reconnect loop in smb2_reconnect() we will immediately wrap retries to -1
and never actually get to pass this conditional:

                if (--retries)
                        continue;

The effect is that we no longer reach the point where we fail the commands with -EHOSTDOWN
and basically the kernel threads are virtually hung and unkillable.

Fixes: a3a53b7603798fd8 (cifs: Add support for failover in smb2_reconnect())
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vfs: fix do_last() regression 2020-02-04T18:18:00+00:00 Al Viro viro@zeniv.linux.org.uk 2020-02-01T16:26:45+00:00 d76341d93dedbcf6ed5a08dfc8bce82d3e9a772b commit 6404674acd596de41fd3ad5f267b4525494a891a upstream. Brown paperbag time: fetching ->i_uid/->i_mode really should've been done from nd->inode. I even suggested that, but the reason for that has slipped through the cracks and I went for dir->d_inode instead - made for more "obvious" patch. Analysis: - at the entry into do_last() and all the way to step_into(): dir (aka nd->path.dentry) is known not to have been freed; so's nd->inode and it's equal to dir->d_inode unless we are already doomed to -ECHILD. inode of the file to get opened is not known. - after step_into(): inode of the file to get opened is known; dir might be pointing to freed memory/be negative/etc. - at the call of may_create_in_sticky(): guaranteed to be out of RCU mode; inode of the file to get opened is known and pinned; dir might be garbage. The last was the reason for the original patch. Except that at the do_last() entry we can be in RCU mode and it is possible that nd->path.dentry->d_inode has already changed under us. In that case we are going to fail with -ECHILD, but we need to be careful; nd->inode is pointing to valid struct inode and it's the same as nd->path.dentry->d_inode in "won't fail with -ECHILD" case, so we should use that. Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" <tommi.t.rantala@nokia.com> Reported-by: syzbot+190005201ced78a74ad6@syzkaller.appspotmail.com Wearing-brown-paperbag: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@kernel.org Fixes: d0cb50185ae9 ("do_last(): fetch directory ->i_mode and ->i_uid before it's too late") Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6404674acd596de41fd3ad5f267b4525494a891a upstream.

Brown paperbag time: fetching ->i_uid/->i_mode really should've been
done from nd->inode.  I even suggested that, but the reason for that has
slipped through the cracks and I went for dir->d_inode instead - made
for more "obvious" patch.

Analysis:

 - at the entry into do_last() and all the way to step_into(): dir (aka
   nd->path.dentry) is known not to have been freed; so's nd->inode and
   it's equal to dir->d_inode unless we are already doomed to -ECHILD.
   inode of the file to get opened is not known.

 - after step_into(): inode of the file to get opened is known; dir
   might be pointing to freed memory/be negative/etc.

 - at the call of may_create_in_sticky(): guaranteed to be out of RCU
   mode; inode of the file to get opened is known and pinned; dir might
   be garbage.

The last was the reason for the original patch.  Except that at the
do_last() entry we can be in RCU mode and it is possible that
nd->path.dentry->d_inode has already changed under us.

In that case we are going to fail with -ECHILD, but we need to be
careful; nd->inode is pointing to valid struct inode and it's the same
as nd->path.dentry->d_inode in "won't fail with -ECHILD" case, so we
should use that.

Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" <tommi.t.rantala@nokia.com>
Reported-by: syzbot+190005201ced78a74ad6@syzkaller.appspotmail.com
Wearing-brown-paperbag: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org
Fixes: d0cb50185ae9 ("do_last(): fetch directory ->i_mode and ->i_uid before it's too late")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: Fix memory allocation in __smb2_handle_cancelled_cmd() 2020-02-01T09:32:56+00:00 Paulo Alcantara (SUSE) pc@cjr.nz 2020-01-13T20:46:59+00:00 21c8990f09eafaafbeb26aacf7f2aabfea180157 commit 0a5a98863c9debc02387b3d23c46d187756f5e2b upstream. __smb2_handle_cancelled_cmd() is called under a spin lock held in cifs_mid_q_entry_release(), so make its memory allocation GFP_ATOMIC. This issue was observed when running xfstests generic/028: [ 1722.589204] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72064 cmd: 5 [ 1722.590687] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72065 cmd: 17 [ 1722.593529] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72066 cmd: 6 [ 1723.039014] BUG: sleeping function called from invalid context at mm/slab.h:565 [ 1723.040710] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 30877, name: cifsd [ 1723.045098] CPU: 3 PID: 30877 Comm: cifsd Not tainted 5.5.0-rc4+ #313 [ 1723.046256] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 [ 1723.048221] Call Trace: [ 1723.048689] dump_stack+0x97/0xe0 [ 1723.049268] ___might_sleep.cold+0xd1/0xe1 [ 1723.050069] kmem_cache_alloc_trace+0x204/0x2b0 [ 1723.051051] __smb2_handle_cancelled_cmd+0x40/0x140 [cifs] [ 1723.052137] smb2_handle_cancelled_mid+0xf6/0x120 [cifs] [ 1723.053247] cifs_mid_q_entry_release+0x44d/0x630 [cifs] [ 1723.054351] ? cifs_reconnect+0x26a/0x1620 [cifs] [ 1723.055325] cifs_demultiplex_thread+0xad4/0x14a0 [cifs] [ 1723.056458] ? cifs_handle_standard+0x2c0/0x2c0 [cifs] [ 1723.057365] ? kvm_sched_clock_read+0x14/0x30 [ 1723.058197] ? sched_clock+0x5/0x10 [ 1723.058838] ? sched_clock_cpu+0x18/0x110 [ 1723.059629] ? lockdep_hardirqs_on+0x17d/0x250 [ 1723.060456] kthread+0x1ab/0x200 [ 1723.061149] ? cifs_handle_standard+0x2c0/0x2c0 [cifs] [ 1723.062078] ? kthread_create_on_node+0xd0/0xd0 [ 1723.062897] ret_from_fork+0x3a/0x50 Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Fixes: 9150c3adbf24 ("CIFS: Close open handle after interrupted close") Cc: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0a5a98863c9debc02387b3d23c46d187756f5e2b upstream.

__smb2_handle_cancelled_cmd() is called under a spin lock held in
cifs_mid_q_entry_release(), so make its memory allocation GFP_ATOMIC.

This issue was observed when running xfstests generic/028:

[ 1722.589204] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72064 cmd: 5
[ 1722.590687] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72065 cmd: 17
[ 1722.593529] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72066 cmd: 6
[ 1723.039014] BUG: sleeping function called from invalid context at mm/slab.h:565
[ 1723.040710] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 30877, name: cifsd
[ 1723.045098] CPU: 3 PID: 30877 Comm: cifsd Not tainted 5.5.0-rc4+ #313
[ 1723.046256] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
[ 1723.048221] Call Trace:
[ 1723.048689]  dump_stack+0x97/0xe0
[ 1723.049268]  ___might_sleep.cold+0xd1/0xe1
[ 1723.050069]  kmem_cache_alloc_trace+0x204/0x2b0
[ 1723.051051]  __smb2_handle_cancelled_cmd+0x40/0x140 [cifs]
[ 1723.052137]  smb2_handle_cancelled_mid+0xf6/0x120 [cifs]
[ 1723.053247]  cifs_mid_q_entry_release+0x44d/0x630 [cifs]
[ 1723.054351]  ? cifs_reconnect+0x26a/0x1620 [cifs]
[ 1723.055325]  cifs_demultiplex_thread+0xad4/0x14a0 [cifs]
[ 1723.056458]  ? cifs_handle_standard+0x2c0/0x2c0 [cifs]
[ 1723.057365]  ? kvm_sched_clock_read+0x14/0x30
[ 1723.058197]  ? sched_clock+0x5/0x10
[ 1723.058838]  ? sched_clock_cpu+0x18/0x110
[ 1723.059629]  ? lockdep_hardirqs_on+0x17d/0x250
[ 1723.060456]  kthread+0x1ab/0x200
[ 1723.061149]  ? cifs_handle_standard+0x2c0/0x2c0 [cifs]
[ 1723.062078]  ? kthread_create_on_node+0xd0/0xd0
[ 1723.062897]  ret_from_fork+0x3a/0x50

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Fixes: 9150c3adbf24 ("CIFS: Close open handle after interrupted close")
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: set correct max-buffer-size for smb2_ioctl_init() 2020-02-01T09:32:56+00:00 Ronnie Sahlberg lsahlber@redhat.com 2020-01-08T03:08:07+00:00 19fe70654458345693696ef1cd3313d1d171ac24 commit 731b82bb1750a906c1e7f070aedf5505995ebea7 upstream. Fix two places where we need to adjust down the max response size for ioctl when it is used together with compounding. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> CC: Stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 731b82bb1750a906c1e7f070aedf5505995ebea7 upstream.

Fix two places where we need to adjust down the max response size for
ioctl when it is used together with compounding.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CIFS: Fix task struct use-after-free on reconnect 2020-02-01T09:32:56+00:00 Vincent Whitchurch vincent.whitchurch@axis.com 2020-01-23T16:09:06+00:00 566881308109de128d5bd88431e295e6142e6324 commit f1f27ad74557e39f67a8331a808b860f89254f2d upstream. The task which created the MID may be gone by the time cifsd attempts to call the callbacks on MIDs from cifs_reconnect(). This leads to a use-after-free of the task struct in cifs_wake_up_task: ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x31a0/0x3270 Read of size 8 at addr ffff8880103e3a68 by task cifsd/630 CPU: 0 PID: 630 Comm: cifsd Not tainted 5.5.0-rc6+ #119 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: dump_stack+0x8e/0xcb print_address_description.constprop.5+0x1d3/0x3c0 ? __lock_acquire+0x31a0/0x3270 __kasan_report+0x152/0x1aa ? __lock_acquire+0x31a0/0x3270 ? __lock_acquire+0x31a0/0x3270 kasan_report+0xe/0x20 __lock_acquire+0x31a0/0x3270 ? __wake_up_common+0x1dc/0x630 ? _raw_spin_unlock_irqrestore+0x4c/0x60 ? mark_held_locks+0xf0/0xf0 ? _raw_spin_unlock_irqrestore+0x39/0x60 ? __wake_up_common_lock+0xd5/0x130 ? __wake_up_common+0x630/0x630 lock_acquire+0x13f/0x330 ? try_to_wake_up+0xa3/0x19e0 _raw_spin_lock_irqsave+0x38/0x50 ? try_to_wake_up+0xa3/0x19e0 try_to_wake_up+0xa3/0x19e0 ? cifs_compound_callback+0x178/0x210 ? set_cpus_allowed_ptr+0x10/0x10 cifs_reconnect+0xa1c/0x15d0 ? generic_ip_connect+0x1860/0x1860 ? rwlock_bug.part.0+0x90/0x90 cifs_readv_from_socket+0x479/0x690 cifs_read_from_socket+0x9d/0xe0 ? cifs_readv_from_socket+0x690/0x690 ? mempool_resize+0x690/0x690 ? rwlock_bug.part.0+0x90/0x90 ? memset+0x1f/0x40 ? allocate_buffers+0xff/0x340 cifs_demultiplex_thread+0x388/0x2a50 ? cifs_handle_standard+0x610/0x610 ? rcu_read_lock_held_common+0x120/0x120 ? mark_lock+0x11b/0xc00 ? __lock_acquire+0x14ed/0x3270 ? __kthread_parkme+0x78/0x100 ? lockdep_hardirqs_on+0x3e8/0x560 ? lock_downgrade+0x6a0/0x6a0 ? lockdep_hardirqs_on+0x3e8/0x560 ? _raw_spin_unlock_irqrestore+0x39/0x60 ? cifs_handle_standard+0x610/0x610 kthread+0x2bb/0x3a0 ? kthread_create_worker_on_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x50 Allocated by task 649: save_stack+0x19/0x70 __kasan_kmalloc.constprop.5+0xa6/0xf0 kmem_cache_alloc+0x107/0x320 copy_process+0x17bc/0x5370 _do_fork+0x103/0xbf0 __x64_sys_clone+0x168/0x1e0 do_syscall_64+0x9b/0xec0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 0: save_stack+0x19/0x70 __kasan_slab_free+0x11d/0x160 kmem_cache_free+0xb5/0x3d0 rcu_core+0x52f/0x1230 __do_softirq+0x24d/0x962 The buggy address belongs to the object at ffff8880103e32c0 which belongs to the cache task_struct of size 6016 The buggy address is located 1960 bytes inside of 6016-byte region [ffff8880103e32c0, ffff8880103e4a40) The buggy address belongs to the page: page:ffffea000040f800 refcount:1 mapcount:0 mapping:ffff8880108da5c0 index:0xffff8880103e4c00 compound_mapcount: 0 raw: 4000000000010200 ffffea00001f2208 ffffea00001e3408 ffff8880108da5c0 raw: ffff8880103e4c00 0000000000050003 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880103e3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880103e3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880103e3a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880103e3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880103e3b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== This can be reliably reproduced by adding the below delay to cifs_reconnect(), running find(1) on the mount, restarting the samba server while find is running, and killing find during the delay: spin_unlock(&GlobalMid_Lock); mutex_unlock(&server->srv_mutex); + msleep(10000); + cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__); list_for_each_safe(tmp, tmp2, &retry_list) { mid_entry = list_entry(tmp, struct mid_q_entry, qhead); Fix this by holding a reference to the task struct until the MID is freed. Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f1f27ad74557e39f67a8331a808b860f89254f2d upstream.

The task which created the MID may be gone by the time cifsd attempts to
call the callbacks on MIDs from cifs_reconnect().

This leads to a use-after-free of the task struct in cifs_wake_up_task:

 ==================================================================
 BUG: KASAN: use-after-free in __lock_acquire+0x31a0/0x3270
 Read of size 8 at addr ffff8880103e3a68 by task cifsd/630

 CPU: 0 PID: 630 Comm: cifsd Not tainted 5.5.0-rc6+ #119
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
 Call Trace:
  dump_stack+0x8e/0xcb
  print_address_description.constprop.5+0x1d3/0x3c0
  ? __lock_acquire+0x31a0/0x3270
  __kasan_report+0x152/0x1aa
  ? __lock_acquire+0x31a0/0x3270
  ? __lock_acquire+0x31a0/0x3270
  kasan_report+0xe/0x20
  __lock_acquire+0x31a0/0x3270
  ? __wake_up_common+0x1dc/0x630
  ? _raw_spin_unlock_irqrestore+0x4c/0x60
  ? mark_held_locks+0xf0/0xf0
  ? _raw_spin_unlock_irqrestore+0x39/0x60
  ? __wake_up_common_lock+0xd5/0x130
  ? __wake_up_common+0x630/0x630
  lock_acquire+0x13f/0x330
  ? try_to_wake_up+0xa3/0x19e0
  _raw_spin_lock_irqsave+0x38/0x50
  ? try_to_wake_up+0xa3/0x19e0
  try_to_wake_up+0xa3/0x19e0
  ? cifs_compound_callback+0x178/0x210
  ? set_cpus_allowed_ptr+0x10/0x10
  cifs_reconnect+0xa1c/0x15d0
  ? generic_ip_connect+0x1860/0x1860
  ? rwlock_bug.part.0+0x90/0x90
  cifs_readv_from_socket+0x479/0x690
  cifs_read_from_socket+0x9d/0xe0
  ? cifs_readv_from_socket+0x690/0x690
  ? mempool_resize+0x690/0x690
  ? rwlock_bug.part.0+0x90/0x90
  ? memset+0x1f/0x40
  ? allocate_buffers+0xff/0x340
  cifs_demultiplex_thread+0x388/0x2a50
  ? cifs_handle_standard+0x610/0x610
  ? rcu_read_lock_held_common+0x120/0x120
  ? mark_lock+0x11b/0xc00
  ? __lock_acquire+0x14ed/0x3270
  ? __kthread_parkme+0x78/0x100
  ? lockdep_hardirqs_on+0x3e8/0x560
  ? lock_downgrade+0x6a0/0x6a0
  ? lockdep_hardirqs_on+0x3e8/0x560
  ? _raw_spin_unlock_irqrestore+0x39/0x60
  ? cifs_handle_standard+0x610/0x610
  kthread+0x2bb/0x3a0
  ? kthread_create_worker_on_cpu+0xc0/0xc0
  ret_from_fork+0x3a/0x50

 Allocated by task 649:
  save_stack+0x19/0x70
  __kasan_kmalloc.constprop.5+0xa6/0xf0
  kmem_cache_alloc+0x107/0x320
  copy_process+0x17bc/0x5370
  _do_fork+0x103/0xbf0
  __x64_sys_clone+0x168/0x1e0
  do_syscall_64+0x9b/0xec0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 Freed by task 0:
  save_stack+0x19/0x70
  __kasan_slab_free+0x11d/0x160
  kmem_cache_free+0xb5/0x3d0
  rcu_core+0x52f/0x1230
  __do_softirq+0x24d/0x962

 The buggy address belongs to the object at ffff8880103e32c0
  which belongs to the cache task_struct of size 6016
 The buggy address is located 1960 bytes inside of
  6016-byte region [ffff8880103e32c0, ffff8880103e4a40)
 The buggy address belongs to the page:
 page:ffffea000040f800 refcount:1 mapcount:0 mapping:ffff8880108da5c0
 index:0xffff8880103e4c00 compound_mapcount: 0
 raw: 4000000000010200 ffffea00001f2208 ffffea00001e3408 ffff8880108da5c0
 raw: ffff8880103e4c00 0000000000050003 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff8880103e3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8880103e3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 >ffff8880103e3a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                           ^
  ffff8880103e3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8880103e3b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ==================================================================

This can be reliably reproduced by adding the below delay to
cifs_reconnect(), running find(1) on the mount, restarting the samba
server while find is running, and killing find during the delay:

  	spin_unlock(&GlobalMid_Lock);
  	mutex_unlock(&server->srv_mutex);

 +	msleep(10000);
 +
  	cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
  	list_for_each_safe(tmp, tmp2, &retry_list) {
  		mid_entry = list_entry(tmp, struct mid_q_entry, qhead);

Fix this by holding a reference to the task struct until the MID is
freed.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
debugfs: Return -EPERM when locked down 2020-02-01T09:32:54+00:00 Eric Snowberg eric.snowberg@oracle.com 2019-12-07T16:16:03+00:00 4dcf9797e5a0b929f2da044afab826d2e74a9036 commit a37f4958f7b63d2b3cd17a76151fdfc29ce1da5f upstream. When lockdown is enabled, debugfs_is_locked_down returns 1. It will then trigger the following: WARNING: CPU: 48 PID: 3747 CPU: 48 PID: 3743 Comm: bash Not tainted 5.4.0-1946.x86_64 #1 Hardware name: Oracle Corporation ORACLE SERVER X7-2/ASM, MB, X7-2, BIOS 41060400 05/20/2019 RIP: 0010:do_dentry_open+0x343/0x3a0 Code: 00 40 08 00 45 31 ff 48 c7 43 28 40 5b e7 89 e9 02 ff ff ff 48 8b 53 28 4c 8b 72 70 4d 85 f6 0f 84 10 fe ff ff e9 f5 fd ff ff <0f> 0b 41 bf ea ff ff ff e9 3b ff ff ff 41 bf e6 ff ff ff e9 b4 fe RSP: 0018:ffffb8740dde7ca0 EFLAGS: 00010202 RAX: ffffffff89e88a40 RBX: ffff928c8e6b6f00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff928dbfd97778 RDI: ffff9285cff685c0 RBP: ffffb8740dde7cc8 R08: 0000000000000821 R09: 0000000000000030 R10: 0000000000000057 R11: ffffb8740dde7a98 R12: ffff926ec781c900 R13: ffff928c8e6b6f10 R14: ffffffff8936e190 R15: 0000000000000001 FS: 00007f45f6777740(0000) GS:ffff928dbfd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff95e0d5d8 CR3: 0000001ece562006 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: vfs_open+0x2d/0x30 path_openat+0x2d4/0x1680 ? tty_mode_ioctl+0x298/0x4c0 do_filp_open+0x93/0x100 ? strncpy_from_user+0x57/0x1b0 ? __alloc_fd+0x46/0x150 do_sys_open+0x182/0x230 __x64_sys_openat+0x20/0x30 do_syscall_64+0x60/0x1b0 entry_SYSCALL_64_after_hwframe+0x170/0x1d5 RIP: 0033:0x7f45f5e5ce02 Code: 25 00 00 41 00 3d 00 00 41 00 74 4c 48 8d 05 25 59 2d 00 8b 00 85 c0 75 6d 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 0f 87 a2 00 00 00 48 8b 4c 24 28 64 48 33 0c 25 RSP: 002b:00007fff95e0d2e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000561178c069b0 RCX: 00007f45f5e5ce02 RDX: 0000000000000241 RSI: 0000561178c08800 RDI: 00000000ffffff9c RBP: 00007fff95e0d3e0 R08: 0000000000000020 R09: 0000000000000005 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000001 R15: 0000561178c08800 Change the return type to int and return -EPERM when lockdown is enabled to remove the warning above. Also rename debugfs_is_locked_down to debugfs_locked_down to make it sound less like it returns a boolean. Fixes: 5496197f9b08 ("debugfs: Restrict debugfs when the kernel is locked down") Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable <stable@vger.kernel.org> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/r/20191207161603.35907-1-eric.snowberg@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a37f4958f7b63d2b3cd17a76151fdfc29ce1da5f upstream.

When lockdown is enabled, debugfs_is_locked_down returns 1. It will then
trigger the following:

WARNING: CPU: 48 PID: 3747
CPU: 48 PID: 3743 Comm: bash Not tainted 5.4.0-1946.x86_64 #1
Hardware name: Oracle Corporation ORACLE SERVER X7-2/ASM, MB, X7-2, BIOS 41060400 05/20/2019
RIP: 0010:do_dentry_open+0x343/0x3a0
Code: 00 40 08 00 45 31 ff 48 c7 43 28 40 5b e7 89 e9 02 ff ff ff 48 8b 53 28 4c 8b 72 70 4d 85 f6 0f 84 10 fe ff ff e9 f5 fd ff ff <0f> 0b 41 bf ea ff ff ff e9 3b ff ff ff 41 bf e6 ff ff ff e9 b4 fe
RSP: 0018:ffffb8740dde7ca0 EFLAGS: 00010202
RAX: ffffffff89e88a40 RBX: ffff928c8e6b6f00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff928dbfd97778 RDI: ffff9285cff685c0
RBP: ffffb8740dde7cc8 R08: 0000000000000821 R09: 0000000000000030
R10: 0000000000000057 R11: ffffb8740dde7a98 R12: ffff926ec781c900
R13: ffff928c8e6b6f10 R14: ffffffff8936e190 R15: 0000000000000001
FS:  00007f45f6777740(0000) GS:ffff928dbfd80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff95e0d5d8 CR3: 0000001ece562006 CR4: 00000000007606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 vfs_open+0x2d/0x30
 path_openat+0x2d4/0x1680
 ? tty_mode_ioctl+0x298/0x4c0
 do_filp_open+0x93/0x100
 ? strncpy_from_user+0x57/0x1b0
 ? __alloc_fd+0x46/0x150
 do_sys_open+0x182/0x230
 __x64_sys_openat+0x20/0x30
 do_syscall_64+0x60/0x1b0
 entry_SYSCALL_64_after_hwframe+0x170/0x1d5
RIP: 0033:0x7f45f5e5ce02
Code: 25 00 00 41 00 3d 00 00 41 00 74 4c 48 8d 05 25 59 2d 00 8b 00 85 c0 75 6d 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 0f 87 a2 00 00 00 48 8b 4c 24 28 64 48 33 0c 25
RSP: 002b:00007fff95e0d2e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000561178c069b0 RCX: 00007f45f5e5ce02
RDX: 0000000000000241 RSI: 0000561178c08800 RDI: 00000000ffffff9c
RBP: 00007fff95e0d3e0 R08: 0000000000000020 R09: 0000000000000005
R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000000001 R15: 0000561178c08800

Change the return type to int and return -EPERM when lockdown is enabled
to remove the warning above. Also rename debugfs_is_locked_down to
debugfs_locked_down to make it sound less like it returns a boolean.

Fixes: 5496197f9b08 ("debugfs: Restrict debugfs when the kernel is locked down")
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable <stable@vger.kernel.org>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Link: https://lore.kernel.org/r/20191207161603.35907-1-eric.snowberg@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge tag 'io_uring-5.5-2020-01-26' of git://git.kernel.dk/linux-block 2020-01-26T20:23:04+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-01-26T20:23:04+00:00 5cf9ad0e6b164a90581a59609dbf5bda3f5a089c Pull io_uring fixes from Jens Axboe: "Fix for two regressions in this cycle, both reported by the postgresql use case. One removes the added restriction on who can submit IO, making it possible for rings shared across forks to do so. The other fixes an issue for the same kind of use case, where one exiting process would cancel all IO" * tag 'io_uring-5.5-2020-01-26' of git://git.kernel.dk/linux-block: io_uring: don't cancel all work on process exit Revert "io_uring: only allow submit from owning task" 
Pull io_uring fixes from Jens Axboe:
 "Fix for two regressions in this cycle, both reported by the postgresql
  use case.

  One removes the added restriction on who can submit IO, making it
  possible for rings shared across forks to do so. The other fixes an
  issue for the same kind of use case, where one exiting process would
  cancel all IO"

* tag 'io_uring-5.5-2020-01-26' of git://git.kernel.dk/linux-block:
  io_uring: don't cancel all work on process exit
  Revert "io_uring: only allow submit from owning task"