[ Upstream commit dd7d37ccf6b11f3d95e797ebe4e9e886d0332600 ]
Although the previous patch can avoid ps and ps UAF for _do_serial, it
can not avoid potential UAF issue for reorder_work. This issue can
happen just as below:
crypto_request crypto_request crypto_del_alg
padata_do_serial
...
padata_reorder
// processes all remaining
// requests then breaks
while (1) {
if (!padata)
break;
...
}
padata_do_serial
// new request added
list_add
// sees the new request
queue_work(reorder_work)
padata_reorder
queue_work_on(squeue->work)
...
<kworker context>
padata_serial_worker
// completes new request,
// no more outstanding
// requests
crypto_del_alg
// free pd
<kworker context>
invoke_padata_reorder
// UAF of pd
To avoid UAF for 'reorder_work', get 'pd' ref before put 'reorder_work'
into the 'serial_wq' and put 'pd' ref until the 'serial_wq' finish.
Fixes: bbefa1dd6a ("crypto: pcrypt - Avoid deadlock by using per-instance padata queues")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ae154202cc6a189b035359f3c4e143d5c24d5352 ]
Add helpers for pd to get/put refcnt to make code consice.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stable-dep-of: dd7d37ccf6b1 ("padata: avoid UAF for reorder_work")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e01780ea4661172734118d2a5f41bc9720765668 ]
A bug was found when run ltp test:
BUG: KASAN: slab-use-after-free in padata_find_next+0x29/0x1a0
Read of size 4 at addr ffff88bbfe003524 by task kworker/u113:2/3039206
CPU: 0 PID: 3039206 Comm: kworker/u113:2 Kdump: loaded Not tainted 6.6.0+
Workqueue: pdecrypt_parallel padata_parallel_worker
Call Trace:
<TASK>
dump_stack_lvl+0x32/0x50
print_address_description.constprop.0+0x6b/0x3d0
print_report+0xdd/0x2c0
kasan_report+0xa5/0xd0
padata_find_next+0x29/0x1a0
padata_reorder+0x131/0x220
padata_parallel_worker+0x3d/0xc0
process_one_work+0x2ec/0x5a0
If 'mdelay(10)' is added before calling 'padata_find_next' in the
'padata_reorder' function, this issue could be reproduced easily with
ltp test (pcrypt_aead01).
This can be explained as bellow:
pcrypt_aead_encrypt
...
padata_do_parallel
refcount_inc(&pd->refcnt); // add refcnt
...
padata_do_serial
padata_reorder // pd
while (1) {
padata_find_next(pd, true); // using pd
queue_work_on
...
padata_serial_worker crypto_del_alg
padata_put_pd_cnt // sub refcnt
padata_free_shell
padata_put_pd(ps->pd);
// pd is freed
// loop again, but pd is freed
// call padata_find_next, UAF
}
In the padata_reorder function, when it loops in 'while', if the alg is
deleted, the refcnt may be decreased to 0 before entering
'padata_find_next', which leads to UAF.
As mentioned in [1], do_serial is supposed to be called with BHs disabled
and always happen under RCU protection, to address this issue, add
synchronize_rcu() in 'padata_free_shell' wait for all _do_serial calls
to finish.
[1] https://lore.kernel.org/all/20221028160401.cccypv4euxikusiq@parnassus.localdomain/
[2] https://lore.kernel.org/linux-kernel/jfjz5d7zwbytztackem7ibzalm5lnxldi2eofeiczqmqs2m7o6@fq426cwnjtkm/
Fixes: b128a30409 ("padata: allocate workqueue internally")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Qu Zicheng <quzicheng@huawei.com>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9ff6e943bce67d125781fe4780a5d6f072dc44c0 ]
padata_sysfs_store() was copied from padata_sysfs_show() but this check
was not adapted. Today there is no attribute which can fail this
check, but if there is one it may as well be correct.
Fixes: 5e017dc3f8 ("padata: Added sysfs primitives to padata subsystem")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8eef6ac4d70eb1f0099fff93321d90ce8fa49ee1 ]
In PREEMPT_RT, kmalloc(GFP_ATOMIC) is still not safe in non preemptible
context. bpf_mem_alloc must be used in PREEMPT_RT. This patch is
to enforce bpf_mem_alloc in the bpf_local_storage when CONFIG_PREEMPT_RT
is enabled.
[ 35.118559] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
[ 35.118566] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1832, name: test_progs
[ 35.118569] preempt_count: 1, expected: 0
[ 35.118571] RCU nest depth: 1, expected: 1
[ 35.118577] INFO: lockdep is turned off.
...
[ 35.118647] __might_resched+0x433/0x5b0
[ 35.118677] rt_spin_lock+0xc3/0x290
[ 35.118700] ___slab_alloc+0x72/0xc40
[ 35.118723] __kmalloc_noprof+0x13f/0x4e0
[ 35.118732] bpf_map_kzalloc+0xe5/0x220
[ 35.118740] bpf_selem_alloc+0x1d2/0x7b0
[ 35.118755] bpf_local_storage_update+0x2fa/0x8b0
[ 35.118784] bpf_sk_storage_get_tracing+0x15a/0x1d0
[ 35.118791] bpf_prog_9a118d86fca78ebb_trace_inet_sock_set_state+0x44/0x66
[ 35.118795] bpf_trace_run3+0x222/0x400
[ 35.118820] __bpf_trace_inet_sock_set_state+0x11/0x20
[ 35.118824] trace_inet_sock_set_state+0x112/0x130
[ 35.118830] inet_sk_state_store+0x41/0x90
[ 35.118836] tcp_set_state+0x3b3/0x640
There is no need to adjust the gfp_flags passing to the
bpf_mem_cache_alloc_flags() which only honors the GFP_KERNEL.
The verifier has ensured GFP_KERNEL is passed only in sleepable context.
It has been an old issue since the first introduction of the
bpf_local_storage ~5 years ago, so this patch targets the bpf-next.
bpf_mem_alloc is needed to solve it, so the Fixes tag is set
to the commit when bpf_mem_alloc was first used in the bpf_local_storage.
Fixes: 08a7ce384e ("bpf: Use bpf_mem_cache_alloc/free in bpf_local_storage_elem")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20241218193000.2084281-1-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8e461a1cb43d69d2fc8a97e61916dce571e6bb31 ]
A redundant frequency update is only truly needed when there is a policy
limits change with a driver that specifies CPUFREQ_NEED_UPDATE_LIMITS.
In spite of that, drivers specifying CPUFREQ_NEED_UPDATE_LIMITS receive a
frequency update _all the time_, not just for a policy limits change,
because need_freq_update is never cleared.
Furthermore, ignore_dl_rate_limit()'s usage of need_freq_update also leads
to a redundant frequency update, regardless of whether or not the driver
specifies CPUFREQ_NEED_UPDATE_LIMITS, when the next chosen frequency is the
same as the current one.
Fix the superfluous updates by only honoring CPUFREQ_NEED_UPDATE_LIMITS
when there's a policy limits change, and clearing need_freq_update when a
requisite redundant update occurs.
This is neatly achieved by moving up the CPUFREQ_NEED_UPDATE_LIMITS test
and instead setting need_freq_update to false in sugov_update_next_freq().
Fixes: 600f5badb7 ("cpufreq: schedutil: Don't skip freq update when limits change")
Signed-off-by: Sultan Alsawaf (unemployed) <sultan@kerneltoast.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20241212015734.41241-2-sultan@kerneltoast.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8d187a77f04c14fb459a5301d69f733a5a1396bc ]
Commit 1b57d91b96 ("irqchip/gic-v2, v3: Prevent SW resends entirely")
sett the flag which enforces interrupt handling in interrupt context and
prevents software base resends for ARM GIC v2/v3.
But it missed that the helper function which checks the flag was hidden
behind CONFIG_GENERIC_PENDING_IRQ, which is not set by ARM[64].
Make the helper unconditionally available so that the enforcement actually
works.
Fixes: 1b57d91b96 ("irqchip/gic-v2, v3: Prevent SW resends entirely")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241210101811.497716609@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f577cd57bfaa889cf0718e30e92c08c7f78c9d85 ]
While reworking the x86 topology code Thomas tripped over creating a 'DIE' domain
for the package mask. :-)
Since these names are CONFIG_SCHED_DEBUG=y only, rename them to make the
name less ambiguous.
[ Shrikanth Hegde: rename on s390 as well. ]
[ Valentin Schneider: also rename it in the comments. ]
[ mingo: port to recent kernels & find all remaining occurances. ]
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Valentin Schneider <vschneid@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230712141056.GI3100107@hirez.programming.kicks-ass.net
Stable-dep-of: e1bc02646527 ("x86/topology: Use x86_sched_itmt_flags for PKG domain unconditionally")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a430d99e349026d53e2557b7b22bd2ebd61fe12a ]
In /proc/schedstat, lb_hot_gained reports the number hot tasks pulled
during load balance. This value is incremented in can_migrate_task()
if the task is migratable and hot. After incrementing the value,
load balancer can still decide not to migrate this task leading to wrong
accounting. Fix this by incrementing stats when hot tasks are detached.
This issue only exists in detach_tasks() where we can decide to not
migrate hot task even if it is migratable. However, in detach_one_task(),
we migrate it unconditionally.
[Swapnil: Handled the case where nr_failed_migrations_hot was not accounted properly and wrote commit log]
Fixes: d31980846f ("sched: Move up affinity check to mitigate useless redoing overhead")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: "Gautham R. Shenoy" <gautham.shenoy@amd.com>
Not-yet-signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241220063224.17767-2-swapnil.sapkal@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b9c44b91476b67327a521568a854babecc4070ab ]
Currently, space for raw sample data is always allocated within sample
records for both BPF output and tracepoint events. This leads to unused
space in sample records when raw sample data is not requested.
This patch enforces checking sample type of an event in
perf_sample_save_raw_data(). So raw sample data will only be saved if
explicitly requested, reducing overhead when it is not needed.
Fixes: 0a9081cf0a ("perf/core: Add perf_sample_save_raw_data() helper")
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515193610.2350456-2-yabinc@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 2f8dea1692eef2b7ba6a256246ed82c365fdc686 upstream.
Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway
through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to
CPUHP_ONLINE:
Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set
to 1 throughout. However, during a CPU unplug operation, the tick and the
clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online
state, for instance CFS incorrectly assumes that the hrtick is already
active, and the chance of the clockevent device to transition to oneshot
mode is also lost forever for the CPU, unless it goes back to a lower state
than CPUHP_HRTIMERS_PREPARE once.
This round-trip reveals another issue; cpu_base.online is not set to 1
after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer().
Aside of that, the bulk of the per CPU state is not reset either, which
means there are dangling pointers in the worst case.
Address this by adding a corresponding startup() callback, which resets the
stale per CPU state and sets the online flag.
[ tglx: Make the new callback unconditionally available, remove the online
modification in the prepare() callback and clear the remaining
state in the starting callback instead of the prepare callback ]
Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier")
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20241220134421.3809834-1-koichiro.den@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 973b710b8821c3401ad7a25360c89e94b26884ac ]
Tell tar to ignore silly-rename files (".__afs*" and ".nfs*") when building
the header archive. These occur when a file that is open is unlinked
locally, but hasn't yet been closed. Such files are visible to the user
via the getdents() syscall and so programs may want to do things with them.
During the kernel build, such files may be made during the processing of
header files and the cleanup may get deferred by fput() which may result in
tar seeing these files when it reads the directory, but they may have
disappeared by the time it tries to open them, causing tar to fail with an
error. Further, we don't want to include them in the tarball if they still
exist.
With CONFIG_HEADERS_INSTALL=y, something like the following may be seen:
find: './kernel/.tmp_cpio_dir/include/dt-bindings/reset/.__afs2080': No such file or directory
tar: ./include/linux/greybus/.__afs3C95: File removed before we read it
The find warning doesn't seem to cause a problem.
Fix this by telling tar when called from in gen_kheaders.sh to exclude such
files. This only affects afs and nfs; cifs uses the Windows Hidden
attribute to prevent the file from being seen.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241213135013.2964079-2-dhowells@redhat.com
cc: Masahiro Yamada <masahiroy@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-kernel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit de35994ecd2dd6148ab5a6c5050a1670a04dec77 ]
After commit
746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM")
amdgpu started seeing the following warning:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu]
...
[ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched]
...
[ ] Call Trace:
[ ] <TASK>
...
[ ] ? check_flush_dependency+0xf5/0x110
...
[ ] cancel_delayed_work_sync+0x6e/0x80
[ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu]
[ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu]
[ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu]
[ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched]
[ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu]
[ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched]
[ ] process_one_work+0x217/0x720
...
[ ] </TASK>
The intent of the verifcation done in check_flush_depedency is to ensure
forward progress during memory reclaim, by flagging cases when either a
memory reclaim process, or a memory reclaim work item is flushed from a
context not marked as memory reclaim safe.
This is correct when flushing, but when called from the
cancel(_delayed)_work_sync() paths it is a false positive because work is
either already running, or will not be running at all. Therefore
cancelling it is safe and we can relax the warning criteria by letting the
helper know of the calling context.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Fixes: fca839c00a ("workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue")
References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM")
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c35aea39d1e106f61fd2130f0d32a3bac8bd4570 ]
These changes are in preparation of BH workqueue which will execute work
items from BH context.
- Update lock and RCU depth checks in process_one_work() so that it
remembers and checks against the starting depths and prints out the depth
changes.
- Factor out lockdep annotations in the flush paths into
touch_{wq|work}_lockdep_map(). The work->lockdep_map touching is moved
from __flush_work() to its callee - start_flush_work(). This brings it
closer to the wq counterpart and will allow testing the associated wq's
flags which will be needed to support BH workqueues. This is not expected
to cause any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Allen Pais <allen.lkml@gmail.com>
Stable-dep-of: de35994ecd2d ("workqueue: Do not warn when cancelling WQ_MEM_RECLAIM work from !WQ_MEM_RECLAIM worker")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1a65a6d17cbc58e1aeffb2be962acce49efbef9c ]
Currently the workqueue just checks the atomic and locking states after work
execution ends. However, sometimes, a work item may not unlock rcu after
acquiring rcu_read_lock(). And as a result, it would cause rcu stall, but
the rcu stall warning can not dump the work func, because the work has
finished.
In order to quickly discover those works that do not call rcu_read_unlock()
after rcu_read_lock(), add the rcu lock check.
Use rcu_preempt_depth() to check the work's rcu status. Normally, this value
is 0. If this value is bigger than 0, it means the work are still holding
rcu lock. If so, print err info and the work func.
tj: Reworded the description for clarity. Minor formatting tweak.
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Stable-dep-of: de35994ecd2d ("workqueue: Do not warn when cancelling WQ_MEM_RECLAIM work from !WQ_MEM_RECLAIM worker")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c4441ca86afe4814039ee1b32c39d833c1a16bbc ]
The bpf_remove_insns() function returns WARN_ON_ONCE(error), where
error is a result of bpf_adj_branches(), and thus should be always 0
However, if for any reason it is not 0, then it will be converted to
boolean by WARN_ON_ONCE and returned to user space as 1, not an actual
error value. Fix this by returning the original err after the WARN check.
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241210114245.836164-1-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit afd2627f727b89496d79a6b934a025fc916d4ded ]
The TP_printk() portion of a trace event is executed at the time a event
is read from the trace. This can happen seconds, minutes, hours, days,
months, years possibly later since the event was recorded. If the print
format contains a dereference to a string via "%s", and that string was
allocated, there's a chance that string could be freed before it is read
by the trace file.
To protect against such bugs, there are two functions that verify the
event. The first one is test_event_printk(), which is called when the
event is created. It reads the TP_printk() format as well as its arguments
to make sure nothing may be dereferencing a pointer that was not copied
into the ring buffer along with the event. If it is, it will trigger a
WARN_ON().
For strings that use "%s", it is not so easy. The string may not reside in
the ring buffer but may still be valid. Strings that are static and part
of the kernel proper which will not be freed for the life of the running
system, are safe to dereference. But to know if it is a pointer to a
static string or to something on the heap can not be determined until the
event is triggered.
This brings us to the second function that tests for the bad dereferencing
of strings, trace_check_vprintf(). It would walk through the printf format
looking for "%s", and when it finds it, it would validate that the pointer
is safe to read. If not, it would produces a WARN_ON() as well and write
into the ring buffer "[UNSAFE-MEMORY]".
The problem with this is how it used va_list to have vsnprintf() handle
all the cases that it didn't need to check. Instead of re-implementing
vsnprintf(), it would make a copy of the format up to the %s part, and
call vsnprintf() with the current va_list ap variable, where the ap would
then be ready to point at the string in question.
For architectures that passed va_list by reference this was possible. For
architectures that passed it by copy it was not. A test_can_verify()
function was used to differentiate between the two, and if it wasn't
possible, it would disable it.
Even for architectures where this was feasible, it was a stretch to rely
on such a method that is undocumented, and could cause issues later on
with new optimizations of the compiler.
Instead, the first function test_event_printk() was updated to look at
"%s" as well. If the "%s" argument is a pointer outside the event in the
ring buffer, it would find the field type of the event that is the problem
and mark the structure with a new flag called "needs_test". The event
itself will be marked by TRACE_EVENT_FL_TEST_STR to let it be known that
this event has a field that needs to be verified before the event can be
printed using the printf format.
When the event fields are created from the field type structure, the
fields would copy the field type's "needs_test" value.
Finally, before being printed, a new function ignore_event() is called
which will check if the event has the TEST_STR flag set (if not, it
returns false). If the flag is set, it then iterates through the events
fields looking for the ones that have the "needs_test" flag set.
Then it uses the offset field from the field structure to find the pointer
in the ring buffer event. It runs the tests to make sure that pointer is
safe to print and if not, it triggers the WARN_ON() and also adds to the
trace output that the event in question has an unsafe memory access.
The ignore_event() makes the trace_check_vprintf() obsolete so it is
removed.
Link: https://lore.kernel.org/all/CAHk-=wh3uOnqnZPpR0PeLZZtyWbZLboZ7cHLCKRWsocvs9Y7hQ@mail.gmail.com/
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20241217024720.848621576@goodmis.org
Fixes: 5013f454a3 ("tracing: Add check of trace event print fmts for dereferencing pointers")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 50a3242d84ee1625b0bfef29b95f935958dccfbe ]
When the tp_printk kernel command line is used, the trace events go
directly to printk(). It is still checked via the trace_check_vprintf()
function to make sure the pointers of the trace event are legit.
The addition of reading buffers from previous boots required adding a
delta between the addresses of the previous boot and the current boot so
that the pointers in the old buffer can still be used. But this required
adding a trace_array pointer to acquire the delta offsets.
The tp_printk code does not provide a trace_array (tr) pointer, so when
the offsets were examined, a NULL pointer dereference happened and the
kernel crashed.
If the trace_array does not exist, just default the delta offsets to zero,
as that also means the trace event is not being read from a previous boot.
Link: https://lore.kernel.org/all/Zv3z5UsG_jsO9_Tb@aschofie-mobl2.lan/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241003104925.4e1b1fd9@gandalf.local.home
Fixes: 07714b4bb3f98 ("tracing: Handle old buffer mappings for event strings and functions")
Reported-by: Alison Schofield <alison.schofield@intel.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Stable-dep-of: afd2627f727b ("tracing: Check "%s" dereference via the field and not the TP_printk format")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit afc6717628f959941d7b33728570568b4af1c4b8 upstream.
In order to catch a common bug where a TRACE_EVENT() TP_fast_assign()
assigns an address of an allocated string to the ring buffer and then
references it in TP_printk(), which can be executed hours later when the
string is free, the function test_event_printk() runs on all events as
they are registered to make sure there's no unwanted dereferencing.
It calls process_string() to handle cases in TP_printk() format that has
"%s". It returns whether or not the string is safe. But it can have some
false positives.
For instance, xe_bo_move() has:
TP_printk("move_lacks_source:%s, migrate object %p [size %zu] from %s to %s device_id:%s",
__entry->move_lacks_source ? "yes" : "no", __entry->bo, __entry->size,
xe_mem_type_to_name[__entry->old_placement],
xe_mem_type_to_name[__entry->new_placement], __get_str(device_id))
Where the "%s" references into xe_mem_type_to_name[]. This is an array of
pointers that should be safe for the event to access. Instead of flagging
this as a bad reference, if a reference points to an array, where the
record field is the index, consider it safe.
Link: https://lore.kernel.org/all/9dee19b6185d325d0e6fa5f7cbba81d007d99166.camel@sapience.com/
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241231000646.324fb5f7@gandalf.local.home
Fixes: 65a25d9f7ac02 ("tracing: Add "%s" check in test_event_printk()")
Reported-by: Genes Lists <lists@sapience.com>
Tested-by: Gene C <arch@sapience.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
