With commit df323337e5 ("apparmor: Use a memory pool instead per-CPU
caches, 2019-05-03"), AppArmor code was converted to use memory pools. In
that conversion, a bug snuck into the code that polices bind mounts that
causes all bind mounts to fail with -ENOMEM, as we erroneously error out
if `aa_get_buffer` returns a pointer instead of erroring out when it
does _not_ return a valid pointer.
Fix the issue by correctly checking for valid pointers returned by
`aa_get_buffer` to fix bind mounts with AppArmor.
Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: John Johansen <john.johansen@canonical.com>
- increase left match history buffer size to provide inproved conflict
resolution in overlapping execution rules.
- switch buffer allocation to use a memory pool and GFP_KERNEL
where possible.
- add compression of policy blobs to reduce memory usage.
+ Cleanups
- fix spelling mistake "immutible" -> "immutable"
+ Bug fixes
- fix unsigned len comparison in update_for_len macro
- fix sparse warning for type-casting of current->real_cred
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Merge tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor updates from John Johansen:
"Features:
- increase left match history buffer size to provide improved
conflict resolution in overlapping execution rules.
- switch buffer allocation to use a memory pool and GFP_KERNEL where
possible.
- add compression of policy blobs to reduce memory usage.
Cleanups:
- fix spelling mistake "immutible" -> "immutable"
Bug fixes:
- fix unsigned len comparison in update_for_len macro
- fix sparse warning for type-casting of current->real_cred"
* tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
apparmor: make it so work buffers can be allocated from atomic context
apparmor: reduce rcu_read_lock scope for aa_file_perm mediation
apparmor: fix wrong buffer allocation in aa_new_mount
apparmor: fix unsigned len comparison with less than zero
apparmor: increase left match history buffer size
apparmor: Switch to GFP_KERNEL where possible
apparmor: Use a memory pool instead per-CPU caches
apparmor: Force type-casting of current->real_cred
apparmor: fix spelling mistake "immutible" -> "immutable"
apparmor: fix blob compression when ns is forced on a policy load
apparmor: fix missing ZLIB defines
apparmor: fix blob compression build failure on ppc
apparmor: Initial implementation of raw policy blob compression
In some situations AppArmor needs to be able to use its work buffers
from atomic context. Add the ability to specify when in atomic context
and hold a set of work buffers in reserve for atomic context to
reduce the chance that a large work buffer allocation will need to
be done.
Fixes: df323337e5 ("apparmor: Use a memory pool instead per-CPU caches")
Signed-off-by: John Johansen <john.johansen@canonical.com>
After removing preempt_disable() from get_buffers() it is possible to
replace a few GFP_ATOMIC allocations with GFP_KERNEL.
Replace GFP_ATOMIC allocations with GFP_KERNEL where the context looks
to bee preepmtible.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
The get_buffers() macro may provide one or two buffers to the caller.
Those buffers are pre-allocated on init for each CPU. By default it
allocates
2* 2 * MAX_PATH * POSSIBLE_CPU
which equals 64KiB on a system with 4 CPUs or 1MiB with 64 CPUs and so
on.
Replace the per-CPU buffers with a common memory pool which is shared
across all CPUs. The pool grows on demand and never shrinks. The pool
starts with two (UP) or four (SMP) elements. By using this pool it is
possible to request a buffer and keeping preemption enabled which avoids
the hack in profile_transition().
It has been pointed out by Tetsuo Handa that GFP_KERNEL allocations for
small amount of memory do not fail. In order not to have an endless
retry, __GFP_RETRY_MAYFAIL is passed (so the memory allocation is not
repeated until success) and retried once hoping that in the meantime a
buffer has been returned to the pool. Since now NULL is possible all
allocation paths check the buffer pointer and return -ENOMEM on failure.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Only the mount namespace code that implements mount(2) should be using the
MS_* flags. Suppress them inside the kernel unless uapi/linux/mount.h is
included.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Acked-by: Christian Boltz <apparmor@cboltz.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Now that file contexts have been moved into file, and task context
fns() and data have been split from the context, only the cred context
remains in context.h so rename to cred.h to better reflect what it
deals with.
Signed-off-by: John Johansen <john.johansen@canonical.com>
When the mount code was refactored for Labels it was not correctly
updated to check whether policy supported mediation of the mount
class. This causes a regression when the kernel feature set is
reported as supporting mount and policy is pinned to a feature set
that does not support mount mediation.
BugLink: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=882697#41
Fixes: 2ea3ffb778 ("apparmor: add mount mediation")
Reported-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
gcc-4.4 points out suspicious code in compute_mnt_perms, where
the aa_perms structure is only partially initialized before getting
returned:
security/apparmor/mount.c: In function 'compute_mnt_perms':
security/apparmor/mount.c:227: error: 'perms.prompt' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.hide' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.cond' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.complain' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.stop' is used uninitialized in this function
security/apparmor/mount.c:227: error: 'perms.deny' is used uninitialized in this function
Returning or assigning partially initialized structures is a bit tricky,
in particular it is explicitly allowed in c99 to assign a partially
initialized structure to another, as long as only members are read that
have been initialized earlier. Looking at what various compilers do here,
the version that produced the warning copied uninitialized stack data,
while newer versions (and also clang) either set the other members to
zero or don't update the parts of the return buffer that are not modified
in the temporary structure, but they never warn about this.
In case of apparmor, it seems better to be a little safer and always
initialize the aa_perms structure. Most users already do that, this
changes the remaining ones, including the one instance that I got the
warning for.
Fixes: fa488437d0f9 ("apparmor: add mount mediation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
