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  1. 31 5月, 2019 3 次提交
    • D
      xfs: don't overflow xattr listent buffer · e8dbd741
      由 Darrick J. Wong 提交于 
      commit 3b50086f0c0d78c144d9483fa292c1509c931b70 upstream.

For VFS listxattr calls, xfs_xattr_put_listent calls
__xfs_xattr_put_listent twice if it sees an attribute
"trusted.SGI_ACL_FILE": once for that name, and again for
"system.posix_acl_access".  Unfortunately, if we happen to run out of
buffer space while emitting the first name, we set count to -1 (so that
we can feed ERANGE to the caller).  The second invocation doesn't check that
the context parameters make sense and overwrites the byte before the
buffer, triggering a KASAN report:

==================================================================
BUG: KASAN: slab-out-of-bounds in strncpy+0xb3/0xd0
Write of size 1 at addr ffff88807fbd317f by task syz/1113

CPU: 3 PID: 1113 Comm: syz Not tainted 5.0.0-rc6-xfsx #rc6
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 dump_stack+0xcc/0x180
 print_address_description+0x6c/0x23c
 kasan_report.cold.3+0x1c/0x35
 strncpy+0xb3/0xd0
 __xfs_xattr_put_listent+0x1a9/0x2c0 [xfs]
 xfs_attr_list_int_ilocked+0x11af/0x1800 [xfs]
 xfs_attr_list_int+0x20c/0x2e0 [xfs]
 xfs_vn_listxattr+0x225/0x320 [xfs]
 listxattr+0x11f/0x1b0
 path_listxattr+0xbd/0x130
 do_syscall_64+0x139/0x560

While we're at it we add an assert to the other put_listent to avoid
this sort of thing ever happening to the attrlist_by_handle code.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      e8dbd741
    • A
      ovl: relax WARN_ON() for overlapping layers use case · ece2e461
      由 Amir Goldstein 提交于 
      commit acf3062a7e1ccf67c6f7e7c28671a6708fde63b0 upstream.

This nasty little syzbot repro:
https://syzkaller.appspot.com/x/repro.syz?x=12c7a94f400000

Creates overlay mounts where the same directory is both in upper and lower
layers. Simplified example:

  mkdir foo work
  mount -t overlay none foo -o"lowerdir=.,upperdir=foo,workdir=work"

The repro runs several threads in parallel that attempt to chdir into foo
and attempt to symlink/rename/exec/mkdir the file bar.

The repro hits a WARN_ON() I placed in ovl_instantiate(), which suggests
that an overlay inode already exists in cache and is hashed by the pointer
of the real upper dentry that ovl_create_real() has just created. At the
point of the WARN_ON(), for overlay dir inode lock is held and upper dir
inode lock, so at first, I did not see how this was possible.

On a closer look, I see that after ovl_create_real(), because of the
overlapping upper and lower layers, a lookup by another thread can find the
file foo/bar that was just created in upper layer, at overlay path
foo/foo/bar and hash the an overlay inode with the new real dentry as lower
dentry. This is possible because the overlay directory foo/foo is not
locked and the upper dentry foo/bar is in dcache, so ovl_lookup() can find
it without taking upper dir inode shared lock.

Overlapping layers is considered a wrong setup which would result in
unexpected behavior, but it shouldn't crash the kernel and it shouldn't
trigger WARN_ON() either, so relax this WARN_ON() and leave a pr_warn()
instead to cover all cases of failure to get an overlay inode.

The error returned from failure to insert new inode to cache with
inode_insert5() was changed to -EEXIST, to distinguish from the error
-ENOMEM returned on failure to get/allocate inode with iget5_locked().

Reported-by: syzbot+9c69c282adc4edd2b540@syzkaller.appspotmail.com
Fixes: 01b39dcc ("ovl: use inode_insert5() to hash a newly...")
Signed-off-by: NAmir Goldstein <amir73il@gmail.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
      ece2e461
    • G
      net/tcp: Support tunable tcp timeout value in TIME-WAIT state · f354337f
      由 George Zhang 提交于 
      By default the tcp_tw_timeout value is 60 seconds. The minimum is
1 second and the maximum is 600. This setting is useful on system under
heavy tcp load.

NOTE: set the tcp_tw_timeout below 60 seconds voilates the "quiet time"
restriction, and make your system into the risk of causing some old data
to be accepted as new or new data rejected as old duplicated by some
receivers.

Link: http://web.archive.org/web/20150102003320/http://tools.ietf.org/html/rfc793Signed-off-by: NGeorge Zhang <georgezhang@linux.alibaba.com>
Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      f354337f
  3. 28 5月, 2019 1 次提交
    • G
      block: Fix a NULL pointer dereference in generic_make_request() · b8cff60d
      由 Guilherme G. Piccoli 提交于 
      Commit 37f9579f ("blk-mq: Avoid that submitting a bio concurrently
with device removal triggers a crash") introduced a NULL pointer
dereference in generic_make_request(). The patch sets q to NULL and
enter_succeeded to false; right after, there's an 'if (enter_succeeded)'
which is not taken, and then the 'else' will dereference q in
blk_queue_dying(q).

This patch just moves the 'q = NULL' to a point in which it won't trigger
the oops, although the semantics of this NULLification remains untouched.

A simple test case/reproducer is as follows:
a) Build kernel v5.2-rc1 with CONFIG_BLK_CGROUP=n.

b) Create a raid0 md array with 2 NVMe devices as members, and mount it
with an ext4 filesystem.

c) Run the following oneliner (supposing the raid0 is mounted in /mnt):
(dd of=/mnt/tmp if=/dev/zero bs=1M count=999 &); sleep 0.3;
echo 1 > /sys/block/nvme0n1/device/device/remove
(whereas nvme0n1 is the 2nd array member)

This will trigger the following oops:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
RIP: 0010:generic_make_request+0x32b/0x400
Call Trace:
 submit_bio+0x73/0x140
 ext4_io_submit+0x4d/0x60
 ext4_writepages+0x626/0xe90
 do_writepages+0x4b/0xe0
[...]

This patch has no functional changes and preserves the md/raid0 behavior
when a member is removed before kernel v4.17.

Cc: stable@vger.kernel.org # v4.17
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Tested-by: NEric Ren <renzhengeek@gmail.com>
Fixes: 37f9579f ("blk-mq: Avoid that submitting a bio concurrently with device removal triggers a crash")
Signed-off-by: NGuilherme G. Piccoli <gpiccoli@canonical.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NEric Ren <renzhen@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      b8cff60d
  5. 25 5月, 2019 1 次提交
  7. 24 5月, 2019 2 次提交
  9. 23 5月, 2019 7 次提交
  11. 18 5月, 2019 1 次提交
  13. 16 5月, 2019 25 次提交