KASAN reported the following issue: [ 36.825817][ T5923] BUG: KASAN: wild-memory-access in v9fs_get_acl+0x1a4/0x390 [ 36.827479][ T5923] Write of size 4 at addr 9fffeb37f97f1c00 by task syz-executor798/5923 [ 36.829303][ T5923] [ 36.829846][ T5923] CPU: 0 PID: 5923 Comm: syz-executor798 Not tainted 6.2.0-syzkaller-18302-g596b6b709632 #0 [ 36.832110][ T5923] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 [ 36.834464][ T5923] Call trace: [ 36.835196][ T5923] dump_backtrace+0x1c8/0x1f4 [ 36.836229][ T5923] show_stack+0x2c/0x3c [ 36.837100][ T5923] dump_stack_lvl+0xd0/0x124 [ 36.838103][ T5923] print_report+0xe4/0x4c0 [ 36.839068][ T5923] kasan_report+0xd4/0x130 [ 36.840052][ T5923] kasan_check_range+0x264/0x2a4 [ 36.841199][ T5923] __kasan_check_write+0x2c/0x3c [ 36.842216][ T5923] v9fs_get_acl+0x1a4/0x390 [ 36.843232][ T5923] v9fs_mount+0x77c/0xa5c [ 36.844163][ T5923] legacy_get_tree+0xd4/0x16c [ 36.845173][ T5923] vfs_get_tree+0x90/0x274 [ 36.846137][ T5923] do_new_mount+0x25c/0x8c8 [ 36.847066][ T5923] path_mount+0x590/0xe58 [ 36.848147][ T5923] __arm64_sys_mount+0x45c/0x594 [ 36.849273][ T5923] invoke_syscall+0x98/0x2c0 [ 36.850421][ T5923] el0_svc_common+0x138/0x258 [ 36.851397][ T5923] do_el0_svc+0x64/0x198 [ 36.852398][ T5923] el0_svc+0x58/0x168 [ 36.853224][ T5923] el0t_64_sync_handler+0x84/0xf0 [ 36.854293][ T5923] el0t_64_sync+0x190/0x194 Calling '__v9fs_get_acl' method in 'v9fs_get_acl' creates the following chain of function calls: __v9fs_get_acl v9fs_fid_get_acl v9fs_fid_xattr_get p9_client_xattrwalk Function p9_client_xattrwalk accepts a pointer to u64-typed variable attr_size and puts some u64 value into it. However, after the executing the p9_client_xattrwalk, in some circumstances we assign the value of u64-typed variable 'attr_size' to the variable 'retval', which we will return. However, the type of 'retval' is ssize_t, and if the value of attr_size is larger than SSIZE_MAX, we will face the signed type overflow. If the overflow occurs, the result of v9fs_fid_xattr_get may be negative, but not classified as an error. When we try to allocate an acl with 'broken' size we receive an error, but don't process it. When we try to free this acl, we face the 'wild-memory-access' error (because it wasn't allocated). This patch will add new condition to the 'v9fs_fid_xattr_get' function, so it will return an EOVERFLOW error if the 'attr_size' is larger than SSIZE_MAX. In this version of the patch I simplified the condition. In previous (v2) version of the patch I removed explicit type conversion and added separate condition to check the possible overflow and return an error (in v1 version I've just modified the existing condition). Tested via syzkaller. Suggested-by: Christian Schoenebeck <linux_oss@crudebyte.com> Reported-by: syzbot+cb1d16facb3cc90de5fb@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=fbbef66d9e4d096242f3617de5d14d12705b4659 Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Pull 9p updates from Eric Van Hensbergen: - some fixes and cleanup setting up for a larger set of performance patches I've been working on - a contributed fixes relating to 9p/rdma - some contributed fixes relating to 9p/xen * tag '9p-6.3-for-linus-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: fs/9p: fix error reporting in v9fs_dir_release net/9p: fix bug in client create for .L 9p/rdma: unmap receive dma buffer in rdma_request()/post_recv() 9p/xen: fix connection sequence 9p/xen: fix version parsing fs/9p: Expand setup of writeback cache to all levels net/9p: Adjust maximum MSIZE to account for p9 header
Checking the p9_fid_put value allows us to pass back errors involved if we end up clunking the fid as part of dir_release. This can help with more graceful response to errors in writeback among other things. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org> Reviewed-by: Dominique Martinet <asmadeus@codewreck.org>
If cache is enabled, make sure we are putting the right things in place (mainly impacts mmap). This also sets us up for more cache levels. Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org> Reviewed-by: Dominique Martinet <asmadeus@codewreck.org>
Pull vfs idmapping updates from Christian Brauner:
- Last cycle we introduced the dedicated struct mnt_idmap type for
mount idmapping and the required infrastucture in 256c8aed2b42 ("fs:
introduce dedicated idmap type for mounts"). As promised in last
cycle's pull request message this converts everything to rely on
struct mnt_idmap.
Currently we still pass around the plain namespace that was attached
to a mount. This is in general pretty convenient but it makes it easy
to conflate namespaces that are relevant on the filesystem with
namespaces that are relevant on the mount level. Especially for
non-vfs developers without detailed knowledge in this area this was a
potential source for bugs.
This finishes the conversion. Instead of passing the plain namespace
around this updates all places that currently take a pointer to a
mnt_userns with a pointer to struct mnt_idmap.
Now that the conversion is done all helpers down to the really
low-level helpers only accept a struct mnt_idmap argument instead of
two namespace arguments.
Conflating mount and other idmappings will now cause the compiler to
complain loudly thus eliminating the possibility of any bugs. This
makes it impossible for filesystem developers to mix up mount and
filesystem idmappings as they are two distinct types and require
distinct helpers that cannot be used interchangeably.
Everything associated with struct mnt_idmap is moved into a single
separate file. With that change no code can poke around in struct
mnt_idmap. It can only be interacted with through dedicated helpers.
That means all filesystems are and all of the vfs is completely
oblivious to the actual implementation of idmappings.
We are now also able to extend struct mnt_idmap as we see fit. For
example, we can decouple it completely from namespaces for users that
don't require or don't want to use them at all. We can also extend
the concept of idmappings so we can cover filesystem specific
requirements.
In combination with the vfs{g,u}id_t work we finished in v6.2 this
makes this feature substantially more robust and thus difficult to
implement wrong by a given filesystem and also protects the vfs.
- Enable idmapped mounts for tmpfs and fulfill a longstanding request.
A long-standing request from users had been to make it possible to
create idmapped mounts for tmpfs. For example, to share the host's
tmpfs mount between multiple sandboxes. This is a prerequisite for
some advanced Kubernetes cases. Systemd also has a range of use-cases
to increase service isolation. And there are more users of this.
However, with all of the other work going on this was way down on the
priority list but luckily someone other than ourselves picked this
up.
As usual the patch is tiny as all the infrastructure work had been
done multiple kernel releases ago. In addition to all the tests that
we already have I requested that Rodrigo add a dedicated tmpfs
testsuite for idmapped mounts to xfstests. It is to be included into
xfstests during the v6.3 development cycle. This should add a slew of
additional tests.
* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
shmem: support idmapped mounts for tmpfs
fs: move mnt_idmap
fs: port vfs{g,u}id helpers to mnt_idmap
fs: port fs{g,u}id helpers to mnt_idmap
fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
fs: port i_{g,u}id_{needs_}update() to mnt_idmap
quota: port to mnt_idmap
fs: port privilege checking helpers to mnt_idmap
fs: port inode_owner_or_capable() to mnt_idmap
fs: port inode_init_owner() to mnt_idmap
fs: port acl to mnt_idmap
fs: port xattr to mnt_idmap
fs: port ->permission() to pass mnt_idmap
fs: port ->fileattr_set() to pass mnt_idmap
fs: port ->set_acl() to pass mnt_idmap
fs: port ->get_acl() to pass mnt_idmap
fs: port ->tmpfile() to pass mnt_idmap
fs: port ->rename() to pass mnt_idmap
fs: port ->mknod() to pass mnt_idmap
fs: port ->mkdir() to pass mnt_idmap
...
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>