The object "ax25_dev" is managed by reference counting. Thus it should
not be directly released by kfree(), replace with ax25_dev_put().
Fixes: d01ffb9eee ("ax25: add refcount in ax25_dev to avoid UAF bugs")
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240530051733.11416-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There is a reference count leak issue of the object "net_device" in
ax25_dev_device_down(). When the ax25 device is shutting down, the
ax25_dev_device_down() drops the reference count of net_device one
or zero times depending on if we goto unlock_put or not, which will
cause memory leak.
In order to solve the above issue, decrease the reference count of
net_device after dev->ax25_ptr is set to null.
Fixes: d01ffb9eee ("ax25: add refcount in ax25_dev to avoid UAF bugs")
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/7ce3b23a40d9084657ba1125432f0ecc380cbc80.1715247018.git.duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The ax25_addr_ax25dev() and ax25_dev_device_down() exist a reference
count leak issue of the object "ax25_dev".
Memory leak issue in ax25_addr_ax25dev():
The reference count of the object "ax25_dev" can be increased multiple
times in ax25_addr_ax25dev(). This will cause a memory leak.
Memory leak issues in ax25_dev_device_down():
The reference count of ax25_dev is set to 1 in ax25_dev_device_up() and
then increase the reference count when ax25_dev is added to ax25_dev_list.
As a result, the reference count of ax25_dev is 2. But when the device is
shutting down. The ax25_dev_device_down() drops the reference count once
or twice depending on if we goto unlock_put or not, which will cause
memory leak.
As for the issue of ax25_addr_ax25dev(), it is impossible for one pointer
to be on a list twice. So add a break in ax25_addr_ax25dev(). As for the
issue of ax25_dev_device_down(), increase the reference count of ax25_dev
once in ax25_dev_device_up() and decrease the reference count of ax25_dev
after it is removed from the ax25_dev_list.
Fixes: d01ffb9eee ("ax25: add refcount in ax25_dev to avoid UAF bugs")
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/361bbf2a4b091e120006279ec3b382d73c4a0c17.1715247018.git.duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The origin ax25_dev_list implements its own single linked list,
which is complicated and error-prone. For example, when deleting
the node of ax25_dev_list in ax25_dev_device_down(), we have to
operate on the head node and other nodes separately.
This patch uses kernel universal linked list to replace original
ax25_dev_list, which make the operation of ax25_dev_list easier.
We should do "dev->ax25_ptr = ax25_dev;" and "dev->ax25_ptr = NULL;"
while holding the spinlock, otherwise the ax25_dev_device_up() and
ax25_dev_device_down() could race.
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/85bba3af651ca0e1a519da8d0d715b949891171c.1715247018.git.duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which will
reduce the overall build time size of the kernel and run time memory
bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
Avoid a buffer overflow when traversing the ctl_table by ensuring that
AX25_MAX_VALUES is the same as the size of ax25_param_table. This is
done with a BUILD_BUG_ON where ax25_param_table is defined and a
CONFIG_AX25_DAMA_SLAVE guard in the unnamed enum definition as well as
in the ax25_dev_device_up and ax25_ds_set_timer functions.
The overflow happened when the sentinel was removed from
ax25_param_table. The sentinel's data element was changed when
CONFIG_AX25_DAMA_SLAVE was undefined. This had no adverse effects as it
still stopped on the sentinel's null procname but needed to be addressed
once the sentinel was removed.
Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the ax25 device is detaching, the ax25_dev_device_down()
calls ax25_ds_del_timer() to cleanup the slave_timer. When
the timer handler is running, the ax25_ds_del_timer() that
calls del_timer() in it will return directly. As a result,
the use-after-free bugs could happen, one of the scenarios
is shown below:
(Thread 1) | (Thread 2)
| ax25_ds_timeout()
ax25_dev_device_down() |
ax25_ds_del_timer() |
del_timer() |
ax25_dev_put() //FREE |
| ax25_dev-> //USE
In order to mitigate bugs, when the device is detaching, use
timer_shutdown_sync() to stop the timer.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240329015023.9223-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ax25_dev_device_up() is only called during device setup, which is
done in user context. In addition, ax25_dev_device_up()
unconditionally calls ax25_register_dev_sysctl(), which already
allocates with GFP_KERNEL.
Since it is allowed to sleep in this function, here we change
ax25_dev_device_up() to use GFP_KERNEL to reduce unnecessary
out-of-memory errors.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Lafreniere <pjlafren@mtu.edu>
Link: https://lore.kernel.org/r/20220616152333.9812-1-pjlafren@mtu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.
Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()
Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There are session cleanup problems in ax25_release() and
ax25_disconnect(). If we setup a session and then disconnect,
the disconnected session is still in "LISTENING" state that
is shown below.
Active AX.25 sockets
Dest Source Device State Vr/Vs Send-Q Recv-Q
DL9SAU-4 DL9SAU-3 ??? LISTENING 000/000 0 0
DL9SAU-3 DL9SAU-4 ??? LISTENING 000/000 0 0
The first reason is caused by del_timer_sync() in ax25_release().
The timers of ax25 are used for correct session cleanup. If we use
ax25_release() to close ax25 sessions and ax25_dev is not null,
the del_timer_sync() functions in ax25_release() will execute.
As a result, the sessions could not be cleaned up correctly,
because the timers have stopped.
In order to solve this problem, this patch adds a device_up flag
in ax25_dev in order to judge whether the device is up. If there
are sessions to be cleaned up, the del_timer_sync() in
ax25_release() will not execute. What's more, we add ax25_cb_del()
in ax25_kill_by_device(), because the timers have been stopped
and there are no functions that could delete ax25_cb if we do not
call ax25_release(). Finally, we reorder the position of
ax25_list_lock in ax25_cb_del() in order to synchronize among
different functions that call ax25_cb_del().
The second reason is caused by improper check in ax25_disconnect().
The incoming ax25 sessions which ax25->sk is null will close
heartbeat timer, because the check "if(!ax25->sk || ..)" is
satisfied. As a result, the session could not be cleaned up properly.
In order to solve this problem, this patch changes the improper
check to "if(ax25->sk && ..)" in ax25_disconnect().
What`s more, the ax25_disconnect() may be called twice, which is
not necessary. For example, ax25_kill_by_device() calls
ax25_disconnect() and sets ax25->state to AX25_STATE_0, but
ax25_release() calls ax25_disconnect() again.
In order to solve this problem, this patch add a check in
ax25_release(). If the flag of ax25->sk equals to SOCK_DEAD,
the ax25_disconnect() in ax25_release() should not be executed.
Fixes: 82e31755e5 ("ax25: Fix UAF bugs in ax25 timers")
Fixes: 8a367e74c0 ("ax25: Fix segfault after sock connection timeout")
Reported-and-tested-by: Thomas Osterried <thomas@osterried.de>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Link: https://lore.kernel.org/r/20220530152158.108619-1-duoming@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The previous commit d01ffb9eee ("ax25: add refcount in ax25_dev
to avoid UAF bugs") introduces refcount into ax25_dev, but there
are reference leak paths in ax25_ctl_ioctl(), ax25_fwd_ioctl(),
ax25_rt_add(), ax25_rt_del() and ax25_rt_opt().
This patch uses ax25_dev_put() and adjusts the position of
ax25_addr_ax25dev() to fix reference cout leaks of ax25_dev.
Fixes: d01ffb9eee ("ax25: add refcount in ax25_dev to avoid UAF bugs")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220203150811.42256-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If we dereference ax25_dev after we call kfree(ax25_dev) in
ax25_dev_device_down(), it will lead to concurrency UAF bugs.
There are eight syscall functions suffer from UAF bugs, include
ax25_bind(), ax25_release(), ax25_connect(), ax25_ioctl(),
ax25_getname(), ax25_sendmsg(), ax25_getsockopt() and
ax25_info_show().
One of the concurrency UAF can be shown as below:
(USE) | (FREE)
| ax25_device_event
| ax25_dev_device_down
ax25_bind | ...
... | kfree(ax25_dev)
ax25_fillin_cb() | ...
ax25_fillin_cb_from_dev() |
... |
The root cause of UAF bugs is that kfree(ax25_dev) in
ax25_dev_device_down() is not protected by any locks.
When ax25_dev, which there are still pointers point to,
is released, the concurrency UAF bug will happen.
This patch introduces refcount into ax25_dev in order to
guarantee that there are no pointers point to it when ax25_dev
is released.
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation for netdev->dev_addr being constant
make all relevant arguments in AX25 constant.
Modify callers as well (netrom, rose).
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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 either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are multiple issues here:
1. After freeing dev->ax25_ptr, we need to set it to NULL otherwise
we may use a dangling pointer.
2. There is a race between ax25_setsockopt() and device notifier as
reported by syzbot. Close it by holding RTNL lock.
3. We need to test if dev->ax25_ptr is NULL before using it.
Reported-and-tested-by: syzbot+ae6bb869cbed29b29040@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't register/unregister every ax25 table in a batch. Instead register
and unregister per device ax25 sysctls as ax25 devices come and go.
This moves ax25 to be a completely modern sysctl user. Registering the
sysctls in just the initial network namespace, removing the use of
.child entries that are no longer natively supported by the sysctl core
and taking advantage of the fact that there are no longer any ordering
constraints between registering and unregistering different sysctl
tables.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:
perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: David Howells <dhowells@redhat.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
This patch changes current use of: init_timer(), add_timer()
and del_timer() to setup_timer() with mod_timer(), which
should be safer anyway.
Reported-by: Jann Traschewski <jann@gmx.de>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
