linux-stable.git/fs, branch v5.4.16 Linux kernel stable tree readdir: be more conservative with directory entry names 2020-01-29T15:45:31+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-01-23T18:05:05+00:00 ab94448beeab30c30c4399b244e65db838be4d64 commit 2c6b7bcd747201441923a0d3062577a8d1fbd8f8 upstream. Commit 8a23eb804ca4 ("Make filldir[64]() verify the directory entry filename is valid") added some minimal validity checks on the directory entries passed to filldir[64](). But they really were pretty minimal. This fleshes out at least the name length check: we used to disallow zero-length names, but really, negative lengths or oevr-long names aren't ok either. Both could happen if there is some filesystem corruption going on. Now, most filesystems tend to use just an "unsigned char" or similar for the length of a directory entry name, so even with a corrupt filesystem you should never see anything odd like that. But since we then use the name length to create the directory entry record length, let's make sure it actually is half-way sensible. Note how POSIX states that the size of a path component is limited by NAME_MAX, but we actually use PATH_MAX for the check here. That's because while NAME_MAX is generally the correct maximum name length (it's 255, for the same old "name length is usually just a byte on disk"), there's nothing in the VFS layer that really cares. So the real limitation at a VFS layer is the total pathname length you can pass as a filename: PATH_MAX. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2c6b7bcd747201441923a0d3062577a8d1fbd8f8 upstream.

Commit 8a23eb804ca4 ("Make filldir[64]() verify the directory entry
filename is valid") added some minimal validity checks on the directory
entries passed to filldir[64]().  But they really were pretty minimal.

This fleshes out at least the name length check: we used to disallow
zero-length names, but really, negative lengths or oevr-long names
aren't ok either.  Both could happen if there is some filesystem
corruption going on.

Now, most filesystems tend to use just an "unsigned char" or similar for
the length of a directory entry name, so even with a corrupt filesystem
you should never see anything odd like that.  But since we then use the
name length to create the directory entry record length, let's make sure
it actually is half-way sensible.

Note how POSIX states that the size of a path component is limited by
NAME_MAX, but we actually use PATH_MAX for the check here.  That's
because while NAME_MAX is generally the correct maximum name length
(it's 255, for the same old "name length is usually just a byte on
disk"), there's nothing in the VFS layer that really cares.

So the real limitation at a VFS layer is the total pathname length you
can pass as a filename: PATH_MAX.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
do_last(): fetch directory ->i_mode and ->i_uid before it's too late 2020-01-29T15:45:31+00:00 Al Viro viro@zeniv.linux.org.uk 2020-01-26T14:29:34+00:00 454759886d0b463213fad0f1c733469e2c501ab9 commit d0cb50185ae942b03c4327be322055d622dc79f6 upstream. may_create_in_sticky() call is done when we already have dropped the reference to dir. Fixes: 30aba6656f61e (namei: allow restricted O_CREAT of FIFOs and regular files) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d0cb50185ae942b03c4327be322055d622dc79f6 upstream.

may_create_in_sticky() call is done when we already have dropped the
reference to dir.

Fixes: 30aba6656f61e (namei: allow restricted O_CREAT of FIFOs and regular files)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
readdir: make user_access_begin() use the real access range 2020-01-29T15:45:29+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-01-22T20:37:25+00:00 376b860334d2b2a0db65396093724b21be2e18a9 commit 3c2659bd1db81ed6a264a9fc6262d51667d655ad upstream. In commit 9f79b78ef744 ("Convert filldir[64]() from __put_user() to unsafe_put_user()") I changed filldir to not do individual __put_user() accesses, but instead use unsafe_put_user() surrounded by the proper user_access_begin/end() pair. That make them enormously faster on modern x86, where the STAC/CLAC games make individual user accesses fairly heavy-weight. However, the user_access_begin() range was not really the exact right one, since filldir() has the unfortunate problem that it needs to not only fill out the new directory entry, it also needs to fix up the previous one to contain the proper file offset. It's unfortunate, but the "d_off" field in "struct dirent" is _not_ the file offset of the directory entry itself - it's the offset of the next one. So we end up backfilling the offset in the previous entry as we walk along. But since x86 didn't really care about the exact range, and used to be the only architecture that did anything fancy in user_access_begin() to begin with, the filldir[64]() changes did something lazy, and even commented on it: /* * Note! This range-checks 'previous' (which may be NULL). * The real range was checked in getdents */ if (!user_access_begin(dirent, sizeof(*dirent))) goto efault; and it all worked fine. But now 32-bit ppc is starting to also implement user_access_begin(), and the fact that we faked the range to only be the (possibly not even valid) previous directory entry becomes a problem, because ppc32 will actually be using the range that is passed in for more than just "check that it's user space". This is a complete rewrite of Christophe's original patch. By saving off the record length of the previous entry instead of a pointer to it in the filldir data structures, we can simplify the range check and the writing of the previous entry d_off field. No need for any conditionals in the user accesses themselves, although we retain the conditional EINTR checking for the "was this the first directory entry" signal handling latency logic. Fixes: 9f79b78ef744 ("Convert filldir[64]() from __put_user() to unsafe_put_user()") Link: https://lore.kernel.org/lkml/a02d3426f93f7eb04960a4d9140902d278cab0bb.1579697910.git.christophe.leroy@c-s.fr/ Link: https://lore.kernel.org/lkml/408c90c4068b00ea8f1c41cca45b84ec23d4946b.1579783936.git.christophe.leroy@c-s.fr/ Reported-and-tested-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3c2659bd1db81ed6a264a9fc6262d51667d655ad upstream.

In commit 9f79b78ef744 ("Convert filldir[64]() from __put_user() to
unsafe_put_user()") I changed filldir to not do individual __put_user()
accesses, but instead use unsafe_put_user() surrounded by the proper
user_access_begin/end() pair.

That make them enormously faster on modern x86, where the STAC/CLAC
games make individual user accesses fairly heavy-weight.

However, the user_access_begin() range was not really the exact right
one, since filldir() has the unfortunate problem that it needs to not
only fill out the new directory entry, it also needs to fix up the
previous one to contain the proper file offset.

It's unfortunate, but the "d_off" field in "struct dirent" is _not_ the
file offset of the directory entry itself - it's the offset of the next
one.  So we end up backfilling the offset in the previous entry as we
walk along.

But since x86 didn't really care about the exact range, and used to be
the only architecture that did anything fancy in user_access_begin() to
begin with, the filldir[64]() changes did something lazy, and even
commented on it:

	/*
	 * Note! This range-checks 'previous' (which may be NULL).
	 * The real range was checked in getdents
	 */
	if (!user_access_begin(dirent, sizeof(*dirent)))
		goto efault;

and it all worked fine.

But now 32-bit ppc is starting to also implement user_access_begin(),
and the fact that we faked the range to only be the (possibly not even
valid) previous directory entry becomes a problem, because ppc32 will
actually be using the range that is passed in for more than just "check
that it's user space".

This is a complete rewrite of Christophe's original patch.

By saving off the record length of the previous entry instead of a
pointer to it in the filldir data structures, we can simplify the range
check and the writing of the previous entry d_off field.  No need for
any conditionals in the user accesses themselves, although we retain the
conditional EINTR checking for the "was this the first directory entry"
signal handling latency logic.

Fixes: 9f79b78ef744 ("Convert filldir[64]() from __put_user() to unsafe_put_user()")
Link: https://lore.kernel.org/lkml/a02d3426f93f7eb04960a4d9140902d278cab0bb.1579697910.git.christophe.leroy@c-s.fr/
Link: https://lore.kernel.org/lkml/408c90c4068b00ea8f1c41cca45b84ec23d4946b.1579783936.git.christophe.leroy@c-s.fr/
Reported-and-tested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ceph: hold extra reference to r_parent over life of request 2020-01-29T15:45:24+00:00 Jeff Layton jlayton@kernel.org 2019-04-03T17:16:01+00:00 fdd0f3b0e98badb7eb2428252f83c2acb494e176 commit 9c1c2b35f1d94de8325344c2777d7ee67492db3b upstream. Currently, we just assume that it will stick around by virtue of the submitter's reference, but later patches will allow the syscall to return early and we can't rely on that reference at that point. While I'm not aware of any reports of it, Xiubo pointed out that this may fix a use-after-free. If the wait for a reply times out or is canceled via signal, and then the reply comes in after the syscall returns, the client can end up trying to access r_parent without a reference. Take an extra reference to the inode when setting r_parent and release it when releasing the request. Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9c1c2b35f1d94de8325344c2777d7ee67492db3b upstream.

Currently, we just assume that it will stick around by virtue of the
submitter's reference, but later patches will allow the syscall to
return early and we can't rely on that reference at that point.

While I'm not aware of any reports of it, Xiubo pointed out that this
may fix a use-after-free.  If the wait for a reply times out or is
canceled via signal, and then the reply comes in after the syscall
returns, the client can end up trying to access r_parent without a
reference.

Take an extra reference to the inode when setting r_parent and release
it when releasing the request.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
afs: Fix characters allowed into cell names 2020-01-29T15:45:24+00:00 David Howells dhowells@redhat.com 2020-01-26T01:02:53+00:00 2d00fec60c8d5c19b0c85936b47ec50ac7917bc5 commit a45ea48e2bcd92c1f678b794f488ca0bda9835b8 upstream. The afs filesystem needs to prohibit certain characters from cell names, such as '/', as these are used to form filenames in procfs, leading to the following warning being generated: WARNING: CPU: 0 PID: 3489 at fs/proc/generic.c:178 Fix afs_alloc_cell() to disallow nonprintable characters, '/', '@' and names that begin with a dot. Remove the check for "@cell" as that is then redundant. This can be tested by running: echo add foo/.bar 1.2.3.4 >/proc/fs/afs/cells Note that we will also need to deal with: - Names ending in ".invalid" shouldn't be passed to the DNS. - Names that contain non-valid domainname chars shouldn't be passed to the DNS. - DNS replies that say "your-dns-needs-immediate-attention.<gTLD>" and replies containing A records that say 127.0.53.53 should be considered invalid. [https://www.icann.org/en/system/files/files/name-collision-mitigation-01aug14-en.pdf] but these need to be dealt with by the kafs-client DNS program rather than the kernel. Reported-by: syzbot+b904ba7c947a37b4b291@syzkaller.appspotmail.com Cc: stable@kernel.org Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a45ea48e2bcd92c1f678b794f488ca0bda9835b8 upstream.

The afs filesystem needs to prohibit certain characters from cell names,
such as '/', as these are used to form filenames in procfs, leading to
the following warning being generated:

	WARNING: CPU: 0 PID: 3489 at fs/proc/generic.c:178

Fix afs_alloc_cell() to disallow nonprintable characters, '/', '@' and
names that begin with a dot.

Remove the check for "@cell" as that is then redundant.

This can be tested by running:

	echo add foo/.bar 1.2.3.4 >/proc/fs/afs/cells

Note that we will also need to deal with:

 - Names ending in ".invalid" shouldn't be passed to the DNS.

 - Names that contain non-valid domainname chars shouldn't be passed to
   the DNS.

 - DNS replies that say "your-dns-needs-immediate-attention.<gTLD>" and
   replies containing A records that say 127.0.53.53 should be
   considered invalid.
   [https://www.icann.org/en/system/files/files/name-collision-mitigation-01aug14-en.pdf]

but these need to be dealt with by the kafs-client DNS program rather
than the kernel.

Reported-by: syzbot+b904ba7c947a37b4b291@syzkaller.appspotmail.com
Cc: stable@kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "io_uring: only allow submit from owning task" 2020-01-29T15:45:24+00:00 Jens Axboe axboe@kernel.dk 2020-01-26T16:53:12+00:00 b29d143a690a660b27e7e84c01dd541d38fe9372 commit 73e08e711d9c1d79fae01daed4b0e1fee5f8a275 upstream. This ends up being too restrictive for tasks that willingly fork and share the ring between forks. Andres reports that this breaks his postgresql work. Since we're close to 5.5 release, revert this change for now. Cc: stable@vger.kernel.org Fixes: 44d282796f81 ("io_uring: only allow submit from owning task") Reported-by: Andres Freund <andres@anarazel.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 73e08e711d9c1d79fae01daed4b0e1fee5f8a275 upstream.

This ends up being too restrictive for tasks that willingly fork and
share the ring between forks. Andres reports that this breaks his
postgresql work. Since we're close to 5.5 release, revert this change
for now.

Cc: stable@vger.kernel.org
Fixes: 44d282796f81 ("io_uring: only allow submit from owning task")
Reported-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
afs: Remove set but not used variables 'before', 'after' 2020-01-26T09:01:08+00:00 zhengbin zhengbin13@huawei.com 2019-11-21T09:12:18+00:00 c1b9854f3e3f9dffc671952a59d652cf9e31afab [ Upstream commit 51590df4f3306cb1f43dca54e3ccdd121ab89594 ] Fixes gcc '-Wunused-but-set-variable' warning: fs/afs/dir_edit.c: In function afs_set_contig_bits: fs/afs/dir_edit.c:75:20: warning: variable after set but not used [-Wunused-but-set-variable] fs/afs/dir_edit.c: In function afs_set_contig_bits: fs/afs/dir_edit.c:75:12: warning: variable before set but not used [-Wunused-but-set-variable] fs/afs/dir_edit.c: In function afs_clear_contig_bits: fs/afs/dir_edit.c:100:20: warning: variable after set but not used [-Wunused-but-set-variable] fs/afs/dir_edit.c: In function afs_clear_contig_bits: fs/afs/dir_edit.c:100:12: warning: variable before set but not used [-Wunused-but-set-variable] They are never used since commit 63a4681ff39c. Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 51590df4f3306cb1f43dca54e3ccdd121ab89594 ]

Fixes gcc '-Wunused-but-set-variable' warning:

fs/afs/dir_edit.c: In function afs_set_contig_bits:
fs/afs/dir_edit.c:75:20: warning: variable after set but not used [-Wunused-but-set-variable]
fs/afs/dir_edit.c: In function afs_set_contig_bits:
fs/afs/dir_edit.c:75:12: warning: variable before set but not used [-Wunused-but-set-variable]
fs/afs/dir_edit.c: In function afs_clear_contig_bits:
fs/afs/dir_edit.c:100:20: warning: variable after set but not used [-Wunused-but-set-variable]
fs/afs/dir_edit.c: In function afs_clear_contig_bits:
fs/afs/dir_edit.c:100:12: warning: variable before set but not used [-Wunused-but-set-variable]

They are never used since commit 63a4681ff39c.

Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
nfsd: depend on CRYPTO_MD5 for legacy client tracking 2020-01-26T09:01:01+00:00 Patrick Steinhardt ps@pks.im 2019-12-04T06:13:22+00:00 cdac80457e88195e82c3bbe197faae89ab98fbaa commit 38a2204f5298620e8a1c3b1dc7b831425106dbc0 upstream. The legacy client tracking infrastructure of nfsd makes use of MD5 to derive a client's recovery directory name. As the nfsd module doesn't declare any dependency on CRYPTO_MD5, though, it may fail to allocate the hash if the kernel was compiled without it. As a result, generation of client recovery directories will fail with the following error: NFSD: unable to generate recoverydir name The explicit dependency on CRYPTO_MD5 was removed as redundant back in 6aaa67b5f3b9 (NFSD: Remove redundant "select" clauses in fs/Kconfig 2008-02-11) as it was already implicitly selected via RPCSEC_GSS_KRB5. This broke when RPCSEC_GSS_KRB5 was made optional for NFSv4 in commit df486a25900f (NFS: Fix the selection of security flavours in Kconfig) at a later point. Fix the issue by adding back an explicit dependency on CRYPTO_MD5. Fixes: df486a25900f (NFS: Fix the selection of security flavours in Kconfig) Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 38a2204f5298620e8a1c3b1dc7b831425106dbc0 upstream.

The legacy client tracking infrastructure of nfsd makes use of MD5 to
derive a client's recovery directory name. As the nfsd module doesn't
declare any dependency on CRYPTO_MD5, though, it may fail to allocate
the hash if the kernel was compiled without it. As a result, generation
of client recovery directories will fail with the following error:

    NFSD: unable to generate recoverydir name

The explicit dependency on CRYPTO_MD5 was removed as redundant back in
6aaa67b5f3b9 (NFSD: Remove redundant "select" clauses in fs/Kconfig
2008-02-11) as it was already implicitly selected via RPCSEC_GSS_KRB5.
This broke when RPCSEC_GSS_KRB5 was made optional for NFSv4 in commit
df486a25900f (NFS: Fix the selection of security flavours in Kconfig) at
a later point.

Fix the issue by adding back an explicit dependency on CRYPTO_MD5.

Fixes: df486a25900f (NFS: Fix the selection of security flavours in Kconfig)
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xfs: Sanity check flags of Q_XQUOTARM call 2020-01-26T09:00:59+00:00 Jan Kara jack@suse.cz 2019-10-24T00:00:45+00:00 dc08e4455a169ac18c7dfba3879aeceaf089f7c8 commit 3dd4d40b420846dd35869ccc8f8627feef2cff32 upstream. Flags passed to Q_XQUOTARM were not sanity checked for invalid values. Fix that. Fixes: 9da93f9b7cdf ("xfs: fix Q_XQUOTARM ioctl") Reported-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3dd4d40b420846dd35869ccc8f8627feef2cff32 upstream.

Flags passed to Q_XQUOTARM were not sanity checked for invalid values.
Fix that.

Fixes: 9da93f9b7cdf ("xfs: fix Q_XQUOTARM ioctl")
Reported-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
reiserfs: fix handling of -EOPNOTSUPP in reiserfs_for_each_xattr 2020-01-23T07:22:57+00:00 Jeff Mahoney jeffm@suse.com 2020-01-15T18:00:59+00:00 5090afc7d1a8bb8021d31e9fc51be80cbc43ed8e commit 394440d469413fa9b74f88a11f144d76017221f2 upstream. Commit 60e4cf67a58 (reiserfs: fix extended attributes on the root directory) introduced a regression open_xa_root started returning -EOPNOTSUPP but it was not handled properly in reiserfs_for_each_xattr. When the reiserfs module is built without CONFIG_REISERFS_FS_XATTR, deleting an inode would result in a warning and chowning an inode would also result in a warning and then fail to complete. With CONFIG_REISERFS_FS_XATTR enabled, the xattr root would always be present for read-write operations. This commit handles -EOPNOSUPP in the same way -ENODATA is handled. Fixes: 60e4cf67a582 ("reiserfs: fix extended attributes on the root directory") CC: stable@vger.kernel.org # Commit 60e4cf67a58 was picked up by stable Link: https://lore.kernel.org/r/20200115180059.6935-1-jeffm@suse.com Reported-by: Michael Brunnbauer <brunni@netestate.de> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 394440d469413fa9b74f88a11f144d76017221f2 upstream.

Commit 60e4cf67a58 (reiserfs: fix extended attributes on the root
directory) introduced a regression open_xa_root started returning
-EOPNOTSUPP but it was not handled properly in reiserfs_for_each_xattr.

When the reiserfs module is built without CONFIG_REISERFS_FS_XATTR,
deleting an inode would result in a warning and chowning an inode
would also result in a warning and then fail to complete.

With CONFIG_REISERFS_FS_XATTR enabled, the xattr root would always be
present for read-write operations.

This commit handles -EOPNOSUPP in the same way -ENODATA is handled.

Fixes: 60e4cf67a582 ("reiserfs: fix extended attributes on the root directory")
CC: stable@vger.kernel.org	# Commit 60e4cf67a58 was picked up by stable
Link: https://lore.kernel.org/r/20200115180059.6935-1-jeffm@suse.com
Reported-by: Michael Brunnbauer <brunni@netestate.de>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>