If the journal is aborted, the needs_recovery feature flag should not
be removed. Otherwise, it's the journal might not get replayed and
this could lead to more data getting lost.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
If the journal has been aborted, we shouldn't mark the underlying
buffer head as dirty, since that will cause the metadata block to get
modified. And if the journal has been aborted, we shouldn't allow
this since it will almost certainly lead to a corrupted file system.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
The write_end() function must always unlock the page and drop its ref
count, even on an error.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
After successful IO or permanent error, b_first_retry_time also
needs to be cleared, else the invalid first retry time will be
used by the next retry check.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Tetsuo has noticed that an OOM stress test which performs large write
requests can cause the full memory reserves depletion. He has tracked
this down to the following path
__alloc_pages_nodemask+0x436/0x4d0
alloc_pages_current+0x97/0x1b0
__page_cache_alloc+0x15d/0x1a0 mm/filemap.c:728
pagecache_get_page+0x5a/0x2b0 mm/filemap.c:1331
grab_cache_page_write_begin+0x23/0x40 mm/filemap.c:2773
iomap_write_begin+0x50/0xd0 fs/iomap.c:118
iomap_write_actor+0xb5/0x1a0 fs/iomap.c:190
? iomap_write_end+0x80/0x80 fs/iomap.c:150
iomap_apply+0xb3/0x130 fs/iomap.c:79
iomap_file_buffered_write+0x68/0xa0 fs/iomap.c:243
? iomap_write_end+0x80/0x80
xfs_file_buffered_aio_write+0x132/0x390 [xfs]
? remove_wait_queue+0x59/0x60
xfs_file_write_iter+0x90/0x130 [xfs]
__vfs_write+0xe5/0x140
vfs_write+0xc7/0x1f0
? syscall_trace_enter+0x1d0/0x380
SyS_write+0x58/0xc0
do_syscall_64+0x6c/0x200
entry_SYSCALL64_slow_path+0x25/0x25
the oom victim has access to all memory reserves to make a forward
progress to exit easier. But iomap_file_buffered_write and other
callers of iomap_apply loop to complete the full request. We need to
check for fatal signals and back off with a short write instead.
As the iomap_apply delegates all the work down to the actor we have to
hook into those. All callers that work with the page cache are calling
iomap_write_begin so we will check for signals there. dax_iomap_actor
has to handle the situation explicitly because it copies data to the
userspace directly. Other callers like iomap_page_mkwrite work on a
single page or iomap_fiemap_actor do not allocate memory based on the
given len.
Fixes: 68a9f5e700 ("xfs: implement iomap based buffered write path")
Link: http://lkml.kernel.org/r/20170201092706.9966-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org> [4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The issue here is that in orangefs_bufmap_alloc() we do:
bufmap->buffer_index_array =
kzalloc(DIV_ROUND_UP(bufmap->desc_count, BITS_PER_LONG), GFP_KERNEL);
If we choose a bufmap->desc_count like -31 then it means the
DIV_ROUND_UP ends up having an integer overflow. The result is that
kzalloc() returns the ZERO_SIZE_PTR and there is a static checker
warning.
But this bug is harmless because on the next lines we use ->desc_count
to do a kcalloc(). That has integer overflow checking built in so the
kcalloc() fails and we return an error code.
Anyway, it doesn't make sense to talk about negative sizes and blocking
them silences the static checker warning.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
Currently, lsattr for instance in udf directory gives
"udf: Invalid argument While reading flags on ..."
This patch returns -ENOIOCTLCMD
when command is unknown to have more accurate message like this:
"Inappropriate ioctl for device While reading flags on ..."
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jan Kara <jack@suse.cz>
It only gets called from aops.c and doesn't appear in any headers.
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Ever since mount propagation was introduced in cases where a mount in
propagated to parent mount mountpoint pair that is already in use the
code has placed the new mount behind the old mount in the mount hash
table.
This implementation detail is problematic as it allows creating
arbitrary length mount hash chains.
Furthermore it invalidates the constraint maintained elsewhere in the
mount code that a parent mount and a mountpoint pair will have exactly
one mount upon them. Making it hard to deal with and to talk about
this special case in the mount code.
Modify mount propagation to notice when there is already a mount at
the parent mount and mountpoint where a new mount is propagating to
and place that preexisting mount on top of the new mount.
Modify unmount propagation to notice when a mount that is being
unmounted has another mount on top of it (and no other children), and
to replace the unmounted mount with the mount on top of it.
Move the MNT_UMUONT test from __lookup_mnt_last into
__propagate_umount as that is the only call of __lookup_mnt_last where
MNT_UMOUNT may be set on any mount visible in the mount hash table.
These modifications allow:
- __lookup_mnt_last to be removed.
- attach_shadows to be renamed __attach_mnt and its shadow
handling to be removed.
- commit_tree to be simplified
- copy_tree to be simplified
The result is an easier to understand tree of mounts that does not
allow creation of arbitrary length hash chains in the mount hash table.
The result is also a very slight userspace visible difference in semantics.
The following two cases now behave identically, where before order
mattered:
case 1: (explicit user action)
B is a slave of A
mount something on A/a , it will propagate to B/a
and than mount something on B/a
case 2: (tucked mount)
B is a slave of A
mount something on B/a
and than mount something on A/a
Histroically umount A/a would fail in case 1 and succeed in case 2.
Now umount A/a succeeds in both configurations.
This very small change in semantics appears if anything to be a bug
fix to me and my survey of userspace leads me to believe that no programs
will notice or care of this subtle semantic change.
v2: Updated to mnt_change_mountpoint to not call dput or mntput
and instead to decrement the counts directly. It is guaranteed
that there will be other references when mnt_change_mountpoint is
called so this is safe.
v3: Moved put_mountpoint under mount_lock in attach_recursive_mnt
As the locking in fs/namespace.c changed between v2 and v3.
v4: Reworked the logic in propagate_mount_busy and __propagate_umount
that detects when a mount completely covers another mount.
v5: Removed unnecessary tests whose result is alwasy true in
find_topper and attach_recursive_mnt.
v6: Document the user space visible semantic difference.
Cc: stable@vger.kernel.org
Fixes: b90fa9ae8f ("[PATCH] shared mount handling: bind and rbind")
Tested-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Michael Kerrisk <<mtk.manpages@gmail.com> writes:
I would like to write code that discovers the namespace setup on a live
system. The NS_GET_PARENT and NS_GET_USERNS ioctl() operations added in
Linux 4.9 provide much of what I want, but there are still a couple of
small pieces missing. Those pieces are added with this patch series.
Here's an example program that makes use of the new ioctl() operations.
8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---
/* ns_capable.c
(C) 2016 Michael Kerrisk, <mtk.manpages@gmail.com>
Licensed under the GNU General Public License v2 or later.
Test whether a process (identified by PID) might (subject to LSM checks)
have capabilities in a namespace (identified by a /proc/PID/ns/xxx file).
*/
} while (0)
exit(EXIT_FAILURE); } while (0)
/* Display capabilities sets of process with specified PID */
static void
show_cap(pid_t pid)
{
cap_t caps;
char *cap_string;
caps = cap_get_pid(pid);
if (caps == NULL)
errExit("cap_get_proc");
cap_string = cap_to_text(caps, NULL);
if (cap_string == NULL)
errExit("cap_to_text");
printf("Capabilities: %s\n", cap_string);
}
/* Obtain the effective UID pf the process 'pid' by
scanning its /proc/PID/file */
static uid_t
get_euid_of_process(pid_t pid)
{
char path[PATH_MAX];
char line[1024];
int uid;
snprintf(path, sizeof(path), "/proc/%ld/status", (long) pid);
FILE *fp;
fp = fopen(path, "r");
if (fp == NULL)
errExit("fopen-/proc/PID/status");
for (;;) {
if (fgets(line, sizeof(line), fp) == NULL) {
/* Should never happen... */
fprintf(stderr, "Failure scanning %s\n", path);
exit(EXIT_FAILURE);
}
if (strstr(line, "Uid:") == line) {
sscanf(line, "Uid: %*d %d %*d %*d", &uid);
return uid;
}
}
}
int
main(int argc, char *argv[])
{
int ns_fd, userns_fd, pid_userns_fd;
int nstype;
int next_fd;
struct stat pid_stat;
struct stat target_stat;
char *pid_str;
pid_t pid;
char path[PATH_MAX];
if (argc < 2) {
fprintf(stderr, "Usage: %s PID [ns-file]\n", argv[0]);
fprintf(stderr, "\t'ns-file' is a /proc/PID/ns/xxxx file; "
"if omitted, use the namespace\n"
"\treferred to by standard input "
"(file descriptor 0)\n");
exit(EXIT_FAILURE);
}
pid_str = argv[1];
pid = atoi(pid_str);
if (argc <= 2) {
ns_fd = STDIN_FILENO;
} else {
ns_fd = open(argv[2], O_RDONLY);
if (ns_fd == -1)
errExit("open-ns-file");
}
/* Get the relevant user namespace FD, which is 'ns_fd' if 'ns_fd' refers
to a user namespace, otherwise the user namespace that owns 'ns_fd' */
nstype = ioctl(ns_fd, NS_GET_NSTYPE);
if (nstype == -1)
errExit("ioctl-NS_GET_NSTYPE");
if (nstype == CLONE_NEWUSER) {
userns_fd = ns_fd;
} else {
userns_fd = ioctl(ns_fd, NS_GET_USERNS);
if (userns_fd == -1)
errExit("ioctl-NS_GET_USERNS");
}
/* Obtain 'stat' info for the user namespace of the specified PID */
snprintf(path, sizeof(path), "/proc/%s/ns/user", pid_str);
pid_userns_fd = open(path, O_RDONLY);
if (pid_userns_fd == -1)
errExit("open-PID");
if (fstat(pid_userns_fd, &pid_stat) == -1)
errExit("fstat-PID");
/* Get 'stat' info for the target user namesapce */
if (fstat(userns_fd, &target_stat) == -1)
errExit("fstat-PID");
/* If the PID is in the target user namespace, then it has
whatever capabilities are in its sets. */
if (pid_stat.st_dev == target_stat.st_dev &&
pid_stat.st_ino == target_stat.st_ino) {
printf("PID is in target namespace\n");
printf("Subject to LSM checks, it has the following capabilities\n");
show_cap(pid);
exit(EXIT_SUCCESS);
}
/* Otherwise, we need to walk through the ancestors of the target
user namespace to see if PID is in an ancestor namespace */
for (;;) {
int f;
next_fd = ioctl(userns_fd, NS_GET_PARENT);
if (next_fd == -1) {
/* The error here should be EPERM... */
if (errno != EPERM)
errExit("ioctl-NS_GET_PARENT");
printf("PID is not in an ancestor namespace\n");
printf("It has no capabilities in the target namespace\n");
exit(EXIT_SUCCESS);
}
if (fstat(next_fd, &target_stat) == -1)
errExit("fstat-PID");
/* If the 'stat' info for this user namespace matches the 'stat'
* info for 'next_fd', then the PID is in an ancestor namespace */
if (pid_stat.st_dev == target_stat.st_dev &&
pid_stat.st_ino == target_stat.st_ino)
break;
/* Next time round, get the next parent */
f = userns_fd;
userns_fd = next_fd;
close(f);
}
/* At this point, we found that PID is in an ancestor of the target
user namespace, and 'userns_fd' refers to the immediate descendant
user namespace of PID in the chain of user namespaces from PID to
the target user namespace. If the effective UID of PID matches the
owner UID of descendant user namespace, then PID has all
capabilities in the descendant namespace(s); otherwise, it just has
the capabilities that are in its sets. */
uid_t owner_uid, uid;
if (ioctl(userns_fd, NS_GET_OWNER_UID, &owner_uid) == -1) {
perror("ioctl-NS_GET_OWNER_UID");
exit(EXIT_FAILURE);
}
uid = get_euid_of_process(pid);
printf("PID is in an ancestor namespace\n");
if (owner_uid == uid) {
printf("And its effective UID matches the owner "
"of the namespace\n");
printf("Subject to LSM checks, PID has all capabilities in "
"that namespace!\n");
} else {
printf("But its effective UID does not match the owner "
"of the namespace\n");
printf("Subject to LSM checks, it has the following capabilities\n");
show_cap(pid);
}
exit(EXIT_SUCCESS);
}
8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---
Michael Kerrisk (2):
nsfs: Add an ioctl() to return the namespace type
nsfs: Add an ioctl() to return owner UID of a userns
fs/nsfs.c | 13 +++++++++++++
include/uapi/linux/nsfs.h | 9 +++++++--
2 files changed, 20 insertions(+), 2 deletions(-)
I'd like to write code that discovers the user namespace hierarchy on a
running system, and also shows who owns the various user namespaces.
Currently, there is no way of getting the owner UID of a user namespace.
Therefore, this patch adds a new NS_GET_CREATOR_UID ioctl() that fetches
the UID (as seen in the user namespace of the caller) of the creator of
the user namespace referred to by the specified file descriptor.
If the supplied file descriptor does not refer to a user namespace,
the operation fails with the error EINVAL. If the owner UID does
not have a mapping in the caller's user namespace return the
overflow UID as that appears easier to deal with in practice
in user-space applications.
-- EWB Changed the handling of unmapped UIDs from -EOVERFLOW
back to the overflow uid. Per conversation with
Michael Kerrisk after examining his test code.
Acked-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Michael Kerrisk <mtk-manpages@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Christoph Hellwig pointed out that there's a potentially nasty race when
performing simultaneous nearby directio cow writes:
"Thread 1 writes a range from B to c
" B --------- C
p
"a little later thread 2 writes from A to B
" A --------- B
p
[editor's note: the 'p' denote cowextsize boundaries, which I added to
make this more clear]
"but the code preallocates beyond B into the range where thread
"1 has just written, but ->end_io hasn't been called yet.
"But once ->end_io is called thread 2 has already allocated
"up to the extent size hint into the write range of thread 1,
"so the end_io handler will splice the unintialized blocks from
"that preallocation back into the file right after B."
We can avoid this race by ensuring that thread 1 cannot accidentally
remap the blocks that thread 2 allocated (as part of speculative
preallocation) as part of t2's write preparation in t1's end_io handler.
The way we make this happen is by taking advantage of the unwritten
extent flag as an intermediate step.
Recall that when we begin the process of writing data to shared blocks,
we create a delayed allocation extent in the CoW fork:
D: --RRRRRRSSSRRRRRRRR---
C: ------DDDDDDD---------
When a thread prepares to CoW some dirty data out to disk, it will now
convert the delalloc reservation into an /unwritten/ allocated extent in
the cow fork. The da conversion code tries to opportunistically
allocate as much of a (speculatively prealloc'd) extent as possible, so
we may end up allocating a larger extent than we're actually writing
out:
D: --RRRRRRSSSRRRRRRRR---
U: ------UUUUUUU---------
Next, we convert only the part of the extent that we're actively
planning to write to normal (i.e. not unwritten) status:
D: --RRRRRRSSSRRRRRRRR---
U: ------UURRUUU---------
If the write succeeds, the end_cow function will now scan the relevant
range of the CoW fork for real extents and remap only the real extents
into the data fork:
D: --RRRRRRRRSRRRRRRRR---
U: ------UU--UUU---------
This ensures that we never obliterate valid data fork extents with
unwritten blocks from the CoW fork.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In the data fork, we only allow extents to perform the following state
transitions:
delay -> real <-> unwritten
There's no way to move directly from a delalloc reservation to an
/unwritten/ allocated extent. However, for the CoW fork we want to be
able to do the following to each extent:
delalloc -> unwritten -> written -> remapped to data fork
This will help us to avoid a race in the speculative CoW preallocation
code between a first thread that is allocating a CoW extent and a second
thread that is remapping part of a file after a write. In order to do
this, however, we need two things: first, we have to be able to
transition from da to unwritten, and second the function that converts
between real and unwritten has to be made aware of the cow fork. Do
both of those things.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Perform basic sanity checking of the directory free block header
fields so that we avoid hanging the system on invalid data.
(Granted that just means that now we shutdown on directory write,
but that seems better than hanging...)
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
We can't handle a bmbt that's taller than BTREE_MAXLEVELS, and there's
no such thing as a zero-level bmbt (for that we have extents format),
so if we see this, send back an error code.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Don't let anybody load an obviously bad btree pointer. Since the values
come from disk, we must return an error, not just ASSERT.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
When we open a directory, we try to readahead block 0 of the directory
on the assumption that we're going to need it soon. If the bmbt is
corrupt, the directory will never be usable and the readahead fails
immediately, so we might as well prevent the directory from being opened
at all. This prevents a subsequent read or modify operation from
hitting it and taking the fs offline.
NOTE: We're only checking for early failures in the block mapping, not
the readahead directory block itself.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
We use di_format and if_flags to decide whether we're grabbing the ilock
in btree mode (btree extents not loaded) or shared mode (anything else),
but the state of those fields can be changed by other threads that are
also trying to load the btree extents -- IFEXTENTS gets set before the
_bmap_read_extents call and cleared if it fails.
We don't actually need to have IFEXTENTS set until after the bmbt
records are successfully loaded and validated, which will fix the race
between multiple threads trying to read the same directory. The next
patch strengthens directory bmbt validation by refusing to open the
directory if reading the bmbt to start directory readahead fails.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Pull nfsd fixes from Bruce Fields:
"Three more miscellaneous nfsd bugfixes"
* tag 'nfsd-4.10-2' of git://linux-nfs.org/~bfields/linux:
svcrpc: fix oops in absence of krb5 module
nfsd: special case truncates some more
NFSD: Fix a null reference case in find_or_create_lock_stateid()
We don't always have easy access to the dentry of a file or directory we
created in debugfs. Add a helper which allows us to get a dentry we
previously created.
The motivation for this change is a problem with blktrace and the blk-mq
debugfs entries introduced in 07e4fead45 ("blk-mq: create debugfs
directory tree"). Namely, in some cases, the directory that blktrace
needs to create may already exist, but in other cases, it may not. We
_could_ rely on a bunch of implied knowledge to decide whether to create
the directory or not, but it's much cleaner on our end to just look it
up.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
The "half md4" transform should not be used by any new code. And
fortunately, it's only used now by ext4. Since ext4 supports several
hashing methods, at some point it might be desirable to move to
something like SipHash. As an intermediate step, remove half md4 from
cryptohash.h and lib, and make it just a local function in ext4's
hash.c. There's precedent for doing this; the other function ext can use
for its hashes -- TEA -- is also implemented in the same place. Also, by
being a local function, this might allow gcc to perform some additional
optimizations.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
blk_get_backing_dev_info() is now a simple dereference. Remove that
function and simplify some code around that.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currenly blk_get_backing_dev_info() is not safe to be called when the
block device is not open as bdev->bd_disk is NULL in that case. However
inode_to_bdi() uses this function and may be call called from flusher
worker or other writeback related functions without bdev being open
which leads to crashes such as:
[113031.075540] Unable to handle kernel paging request for data at address 0x00000000
[113031.075614] Faulting instruction address: 0xc0000000003692e0
0:mon> t
[c0000000fb65f900] c00000000036cb6c writeback_sb_inodes+0x30c/0x590
[c0000000fb65fa10] c00000000036ced4 __writeback_inodes_wb+0xe4/0x150
[c0000000fb65fa70] c00000000036d33c wb_writeback+0x30c/0x450
[c0000000fb65fb40] c00000000036e198 wb_workfn+0x268/0x580
[c0000000fb65fc50] c0000000000f3470 process_one_work+0x1e0/0x590
[c0000000fb65fce0] c0000000000f38c8 worker_thread+0xa8/0x660
[c0000000fb65fd80] c0000000000fc4b0 kthread+0x110/0x130
[c0000000fb65fe30] c0000000000098f0 ret_from_kernel_thread+0x5c/0x6c
Signed-off-by: Jens Axboe <axboe@fb.com>
We will want to have struct backing_dev_info allocated separately from
struct request_queue. As the first step add pointer to backing_dev_info
to request_queue and convert all users touching it. No functional
changes in this patch.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, block device inodes stay around after corresponding gendisk
hash died until memory reclaim finds them and frees them. Since we will
make block device inode pin the bdi, we want to free the block device
inode as soon as the device goes away so that bdi does not stay around
unnecessarily. Furthermore we need to avoid issues when new device with
the same major,minor pair gets created since reusing the bdi structure
would be rather difficult in this case.
Unhashing block device inode on gendisk destruction nicely deals with
these problems. Once last block device inode reference is dropped (which
may be directly in del_gendisk()), the inode gets evicted. Furthermore if
the major,minor pair gets reallocated, we are guaranteed to get new
block device inode even if old block device inode is not yet evicted and
thus we avoid issues with possible reuse of bdi.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
In the case where the child's encryption context was inconsistent with
its parent directory, we were using inode->i_sb and inode->i_ino after
the inode had already been iput(). Fix this by doing the iput() in the
correct places.
Note: only ext4 had this bug, not f2fs and ubifs.
Fixes: d9cdc90331 ("ext4 crypto: enforce context consistency")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Below is the synchronization issue between unmount and kjournald2
contexts, which results into use after free issue in kjournald2().
Fix this issue by using journal->j_state_lock to synchronize the
wait_event() done in journal_kill_thread() and the wake_up() done
in kjournald2().
TASK 1:
umount cmd:
|--jbd2_journal_destroy() {
|--journal_kill_thread() {
write_lock(&journal->j_state_lock);
journal->j_flags |= JBD2_UNMOUNT;
...
write_unlock(&journal->j_state_lock);
wake_up(&journal->j_wait_commit); TASK 2 wakes up here:
kjournald2() {
...
checks JBD2_UNMOUNT flag and calls goto end-loop;
...
end_loop:
write_unlock(&journal->j_state_lock);
journal->j_task = NULL; --> If this thread gets
pre-empted here, then TASK 1 wait_event will
exit even before this thread is completely
done.
wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
...
write_lock(&journal->j_state_lock);
write_unlock(&journal->j_state_lock);
}
|--kfree(journal);
}
}
wake_up(&journal->j_wait_done_commit); --> this step
now results into use after free issue.
}
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Allow to decrypt transformed packets that are bigger than the big
buffer size. In particular it is used for read responses that can
only exceed the big buffer size.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Since we have two different types of reads (pagecache and direct)
we need to process such responses differently after decryption of
a packet. The change allows to specify a callback that copies a read
payload data into preallocated pages.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
We need to process read responses differently because the data
should go directly into preallocated pages. This can be done
by specifying a mid handle callback.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
We need to recognize and parse transformed packets in demultiplex
thread to find a corresponsing mid and process it further.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
This change allows to encrypt packets if it is required by a server
for SMB sessions or tree connections.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
In order to allow encryption on SMB connection we need to exchange
a session key and generate encryption and decryption keys.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
This will allow us to do protocol specific tranformations of packets
before sending to the server. For SMB3 it can be used to support
encryption.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Allocate and initialize SMB2 read request without RFC1001 length
field to directly call cifs_send_recv() rather than SendReceive2()
in a read codepath.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Do not process RFC1001 length in smb2_hdr_assemble() because
it is not a part of SMB2 header. This allows to cleanup the code
and adds a possibility combine several SMB2 packets into one
for compounding.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
In order to simplify further encryption support we need to separate
RFC1001 length and SMB2 header when sending a request. Put the length
field in iov[0] and the rest of the packet into following iovs.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Now SendReceive2 frees the first iov and returns a response buffer
in it that increases a code complexity. Simplify this by making
a caller responsible for freeing request buffer itself and returning
a response buffer in a separate iov.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
In order to support compounding and encryption we need to separate
RFC1001 length field and SMB2 header structure because the protocol
treats them differently. This change will allow to simplify parsing
of such complex SMB2 packets further.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Currently we call copy_page_to_iter() for uncached reading into a pipe.
This is wrong because it treats pages as VFS cache pages and copies references
rather than actual data. When we are trying to read from the pipe we end up
calling page_cache_pipe_buf_confirm() which returns -ENODATA. This error
is translated into 0 which is returned to a user.
This issue is reproduced by running xfs-tests suite (generic test #249)
against mount points with "cache=none". Fix it by mapping pages manually
and calling copy_to_iter() that copies data into the pipe.
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
List soft dependencies of cifs so that mkinitrd and dracut can include
the required helper modules.
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Steve French <sfrench@samba.org>
The sha256 and cmac crypto modules are only needed for SMB2+, so move
the select statements to config CIFS_SMB2. Also select CRYPTO_AES
there as SMB2+ needs it.
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Steve French <sfrench@samba.org>
* CIFS_SMB2 depends on CIFS, which depends on INET and selects NLS. So
these dependencies do not need to be repeated for CIFS_SMB2.
* CIFS_SMB311 depends on CIFS_SMB2, which depends on INET. So this
dependency doesn't need to be repeated for CIFS_SMB311.
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Steve French <sfrench@samba.org>
