linux.git/kernel, branch v5.4.156 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git tracing: Have all levels of checks prevent recursion 2021-10-27T07:54:29+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2021-10-18T19:44:12+00:00 a98c81ab17511704c1140a48b57906a9661cb3f0 commit ed65df63a39a3f6ed04f7258de8b6789e5021c18 upstream. While writing an email explaining the "bit = 0" logic for a discussion on making ftrace_test_recursion_trylock() disable preemption, I discovered a path that makes the "not do the logic if bit is zero" unsafe. The recursion logic is done in hot paths like the function tracer. Thus, any code executed causes noticeable overhead. Thus, tricks are done to try to limit the amount of code executed. This included the recursion testing logic. Having recursion testing is important, as there are many paths that can end up in an infinite recursion cycle when tracing every function in the kernel. Thus protection is needed to prevent that from happening. Because it is OK to recurse due to different running context levels (e.g. an interrupt preempts a trace, and then a trace occurs in the interrupt handler), a set of bits are used to know which context one is in (normal, softirq, irq and NMI). If a recursion occurs in the same level, it is prevented*. Then there are infrastructure levels of recursion as well. When more than one callback is attached to the same function to trace, it calls a loop function to iterate over all the callbacks. Both the callbacks and the loop function have recursion protection. The callbacks use the "ftrace_test_recursion_trylock()" which has a "function" set of context bits to test, and the loop function calls the internal trace_test_and_set_recursion() directly, with an "internal" set of bits. If an architecture does not implement all the features supported by ftrace then the callbacks are never called directly, and the loop function is called instead, which will implement the features of ftrace. Since both the loop function and the callbacks do recursion protection, it was seemed unnecessary to do it in both locations. Thus, a trick was made to have the internal set of recursion bits at a more significant bit location than the function bits. Then, if any of the higher bits were set, the logic of the function bits could be skipped, as any new recursion would first have to go through the loop function. This is true for architectures that do not support all the ftrace features, because all functions being traced must first go through the loop function before going to the callbacks. But this is not true for architectures that support all the ftrace features. That's because the loop function could be called due to two callbacks attached to the same function, but then a recursion function inside the callback could be called that does not share any other callback, and it will be called directly. i.e. traced_function_1: [ more than one callback tracing it ] call loop_func loop_func: trace_recursion set internal bit call callback callback: trace_recursion [ skipped because internal bit is set, return 0 ] call traced_function_2 traced_function_2: [ only traced by above callback ] call callback callback: trace_recursion [ skipped because internal bit is set, return 0 ] call traced_function_2 [ wash, rinse, repeat, BOOM! out of shampoo! ] Thus, the "bit == 0 skip" trick is not safe, unless the loop function is call for all functions. Since we want to encourage architectures to implement all ftrace features, having them slow down due to this extra logic may encourage the maintainers to update to the latest ftrace features. And because this logic is only safe for them, remove it completely. [*] There is on layer of recursion that is allowed, and that is to allow for the transition between interrupt context (normal -> softirq -> irq -> NMI), because a trace may occur before the context update is visible to the trace recursion logic. Link: https://lore.kernel.org/all/609b565a-ed6e-a1da-f025-166691b5d994@linux.alibaba.com/ Link: https://lkml.kernel.org/r/20211018154412.09fcad3c@gandalf.local.home Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@hansenpartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Jisheng Zhang <jszhang@kernel.org> Cc: =?utf-8?b?546L6LSH?= <yun.wang@linux.alibaba.com> Cc: Guo Ren <guoren@kernel.org> Cc: stable@vger.kernel.org Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ed65df63a39a3f6ed04f7258de8b6789e5021c18 upstream.

While writing an email explaining the "bit = 0" logic for a discussion on
making ftrace_test_recursion_trylock() disable preemption, I discovered a
path that makes the "not do the logic if bit is zero" unsafe.

The recursion logic is done in hot paths like the function tracer. Thus,
any code executed causes noticeable overhead. Thus, tricks are done to try
to limit the amount of code executed. This included the recursion testing
logic.

Having recursion testing is important, as there are many paths that can
end up in an infinite recursion cycle when tracing every function in the
kernel. Thus protection is needed to prevent that from happening.

Because it is OK to recurse due to different running context levels (e.g.
an interrupt preempts a trace, and then a trace occurs in the interrupt
handler), a set of bits are used to know which context one is in (normal,
softirq, irq and NMI). If a recursion occurs in the same level, it is
prevented*.

Then there are infrastructure levels of recursion as well. When more than
one callback is attached to the same function to trace, it calls a loop
function to iterate over all the callbacks. Both the callbacks and the
loop function have recursion protection. The callbacks use the
"ftrace_test_recursion_trylock()" which has a "function" set of context
bits to test, and the loop function calls the internal
trace_test_and_set_recursion() directly, with an "internal" set of bits.

If an architecture does not implement all the features supported by ftrace
then the callbacks are never called directly, and the loop function is
called instead, which will implement the features of ftrace.

Since both the loop function and the callbacks do recursion protection, it
was seemed unnecessary to do it in both locations. Thus, a trick was made
to have the internal set of recursion bits at a more significant bit
location than the function bits. Then, if any of the higher bits were set,
the logic of the function bits could be skipped, as any new recursion
would first have to go through the loop function.

This is true for architectures that do not support all the ftrace
features, because all functions being traced must first go through the
loop function before going to the callbacks. But this is not true for
architectures that support all the ftrace features. That's because the
loop function could be called due to two callbacks attached to the same
function, but then a recursion function inside the callback could be
called that does not share any other callback, and it will be called
directly.

i.e.

 traced_function_1: [ more than one callback tracing it ]
   call loop_func

 loop_func:
   trace_recursion set internal bit
   call callback

 callback:
   trace_recursion [ skipped because internal bit is set, return 0 ]
   call traced_function_2

 traced_function_2: [ only traced by above callback ]
   call callback

 callback:
   trace_recursion [ skipped because internal bit is set, return 0 ]
   call traced_function_2

 [ wash, rinse, repeat, BOOM! out of shampoo! ]

Thus, the "bit == 0 skip" trick is not safe, unless the loop function is
call for all functions.

Since we want to encourage architectures to implement all ftrace features,
having them slow down due to this extra logic may encourage the
maintainers to update to the latest ftrace features. And because this
logic is only safe for them, remove it completely.

 [*] There is on layer of recursion that is allowed, and that is to allow
     for the transition between interrupt context (normal -> softirq ->
     irq -> NMI), because a trace may occur before the context update is
     visible to the trace recursion logic.

Link: https://lore.kernel.org/all/609b565a-ed6e-a1da-f025-166691b5d994@linux.alibaba.com/
Link: https://lkml.kernel.org/r/20211018154412.09fcad3c@gandalf.local.home

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Jisheng Zhang <jszhang@kernel.org>
Cc: =?utf-8?b?546L6LSH?= <yun.wang@linux.alibaba.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: stable@vger.kernel.org
Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
audit: fix possible null-pointer dereference in audit_filter_rules 2021-10-27T07:54:27+00:00 Gaosheng Cui cuigaosheng1@huawei.com 2021-10-16T07:23:50+00:00 d6f451f1f60c58d73038c7c3177066f8f084e2a2 commit 6e3ee990c90494561921c756481d0e2125d8b895 upstream. Fix possible null-pointer dereference in audit_filter_rules. audit_filter_rules() error: we previously assumed 'ctx' could be null Cc: stable@vger.kernel.org Fixes: bf361231c295 ("audit: add saddr_fam filter field") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6e3ee990c90494561921c756481d0e2125d8b895 upstream.

Fix  possible null-pointer dereference in audit_filter_rules.

audit_filter_rules() error: we previously assumed 'ctx' could be null

Cc: stable@vger.kernel.org
Fixes: bf361231c295 ("audit: add saddr_fam filter field")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dma-debug: fix sg checks in debug_dma_map_sg() 2021-10-27T07:54:25+00:00 Gerald Schaefer gerald.schaefer@linux.ibm.com 2021-10-06T20:19:43+00:00 0f5b08ca22e1930d2cb0aa176355434b927537bc [ Upstream commit 293d92cbbd2418ca2ba43fed07f1b92e884d1c77 ] The following warning occurred sporadically on s390: DMA-API: nvme 0006:00:00.0: device driver maps memory from kernel text or rodata [addr=0000000048cc5e2f] [len=131072] WARNING: CPU: 4 PID: 825 at kernel/dma/debug.c:1083 check_for_illegal_area+0xa8/0x138 It is a false-positive warning, due to broken logic in debug_dma_map_sg(). check_for_illegal_area() checks for overlay of sg elements with kernel text or rodata. It is called with sg_dma_len(s) instead of s->length as parameter. After the call to ->map_sg(), sg_dma_len() will contain the length of possibly combined sg elements in the DMA address space, and not the individual sg element length, which would be s->length. The check will then use the physical start address of an sg element, and add the DMA length for the overlap check, which could result in the false warning, because the DMA length can be larger than the actual single sg element length. In addition, the call to check_for_illegal_area() happens in the iteration over mapped_ents, which will not include all individual sg elements if any of them were combined in ->map_sg(). Fix this by using s->length instead of sg_dma_len(s). Also put the call to check_for_illegal_area() in a separate loop, iterating over all the individual sg elements ("nents" instead of "mapped_ents"). While at it, as suggested by Robin Murphy, also move check_for_stack() inside the new loop, as it is similarly concerned with validating the individual sg elements. Link: https://lore.kernel.org/lkml/20210705185252.4074653-1-gerald.schaefer@linux.ibm.com Fixes: 884d05970bfb ("dma-debug: use sg_dma_len accessor") Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 293d92cbbd2418ca2ba43fed07f1b92e884d1c77 ]

The following warning occurred sporadically on s390:
DMA-API: nvme 0006:00:00.0: device driver maps memory from kernel text or rodata [addr=0000000048cc5e2f] [len=131072]
WARNING: CPU: 4 PID: 825 at kernel/dma/debug.c:1083 check_for_illegal_area+0xa8/0x138

It is a false-positive warning, due to broken logic in debug_dma_map_sg().
check_for_illegal_area() checks for overlay of sg elements with kernel text
or rodata. It is called with sg_dma_len(s) instead of s->length as
parameter. After the call to ->map_sg(), sg_dma_len() will contain the
length of possibly combined sg elements in the DMA address space, and not
the individual sg element length, which would be s->length.

The check will then use the physical start address of an sg element, and
add the DMA length for the overlap check, which could result in the false
warning, because the DMA length can be larger than the actual single sg
element length.

In addition, the call to check_for_illegal_area() happens in the iteration
over mapped_ents, which will not include all individual sg elements if
any of them were combined in ->map_sg().

Fix this by using s->length instead of sg_dma_len(s). Also put the call to
check_for_illegal_area() in a separate loop, iterating over all the
individual sg elements ("nents" instead of "mapped_ents").

While at it, as suggested by Robin Murphy, also move check_for_stack()
inside the new loop, as it is similarly concerned with validating the
individual sg elements.

Link: https://lore.kernel.org/lkml/20210705185252.4074653-1-gerald.schaefer@linux.ibm.com
Fixes: 884d05970bfb ("dma-debug: use sg_dma_len accessor")
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Fix integer overflow in prealloc_elems_and_freelist() 2021-10-13T08:08:18+00:00 Tatsuhiko Yasumatsu th.yasumatsu@gmail.com 2021-09-30T13:55:45+00:00 b14f28126c51533bb329379f65de5b0dd689b13a [ Upstream commit 30e29a9a2bc6a4888335a6ede968b75cd329657a ] In prealloc_elems_and_freelist(), the multiplication to calculate the size passed to bpf_map_area_alloc() could lead to an integer overflow. As a result, out-of-bounds write could occur in pcpu_freelist_populate() as reported by KASAN: [...] [ 16.968613] BUG: KASAN: slab-out-of-bounds in pcpu_freelist_populate+0xd9/0x100 [ 16.969408] Write of size 8 at addr ffff888104fc6ea0 by task crash/78 [ 16.970038] [ 16.970195] CPU: 0 PID: 78 Comm: crash Not tainted 5.15.0-rc2+ #1 [ 16.970878] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 [ 16.972026] Call Trace: [ 16.972306] dump_stack_lvl+0x34/0x44 [ 16.972687] print_address_description.constprop.0+0x21/0x140 [ 16.973297] ? pcpu_freelist_populate+0xd9/0x100 [ 16.973777] ? pcpu_freelist_populate+0xd9/0x100 [ 16.974257] kasan_report.cold+0x7f/0x11b [ 16.974681] ? pcpu_freelist_populate+0xd9/0x100 [ 16.975190] pcpu_freelist_populate+0xd9/0x100 [ 16.975669] stack_map_alloc+0x209/0x2a0 [ 16.976106] __sys_bpf+0xd83/0x2ce0 [...] The possibility of this overflow was originally discussed in [0], but was overlooked. Fix the integer overflow by changing elem_size to u64 from u32. [0] https://lore.kernel.org/bpf/728b238e-a481-eb50-98e9-b0f430ab01e7@gmail.com/ Fixes: 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation") Signed-off-by: Tatsuhiko Yasumatsu <th.yasumatsu@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210930135545.173698-1-th.yasumatsu@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 30e29a9a2bc6a4888335a6ede968b75cd329657a ]

In prealloc_elems_and_freelist(), the multiplication to calculate the
size passed to bpf_map_area_alloc() could lead to an integer overflow.
As a result, out-of-bounds write could occur in pcpu_freelist_populate()
as reported by KASAN:

[...]
[   16.968613] BUG: KASAN: slab-out-of-bounds in pcpu_freelist_populate+0xd9/0x100
[   16.969408] Write of size 8 at addr ffff888104fc6ea0 by task crash/78
[   16.970038]
[   16.970195] CPU: 0 PID: 78 Comm: crash Not tainted 5.15.0-rc2+ #1
[   16.970878] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
[   16.972026] Call Trace:
[   16.972306]  dump_stack_lvl+0x34/0x44
[   16.972687]  print_address_description.constprop.0+0x21/0x140
[   16.973297]  ? pcpu_freelist_populate+0xd9/0x100
[   16.973777]  ? pcpu_freelist_populate+0xd9/0x100
[   16.974257]  kasan_report.cold+0x7f/0x11b
[   16.974681]  ? pcpu_freelist_populate+0xd9/0x100
[   16.975190]  pcpu_freelist_populate+0xd9/0x100
[   16.975669]  stack_map_alloc+0x209/0x2a0
[   16.976106]  __sys_bpf+0xd83/0x2ce0
[...]

The possibility of this overflow was originally discussed in [0], but
was overlooked.

Fix the integer overflow by changing elem_size to u64 from u32.

  [0] https://lore.kernel.org/bpf/728b238e-a481-eb50-98e9-b0f430ab01e7@gmail.com/

Fixes: 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation")
Signed-off-by: Tatsuhiko Yasumatsu <th.yasumatsu@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210930135545.173698-1-th.yasumatsu@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
cpufreq: schedutil: Use kobject release() method to free sugov_tunables 2021-10-06T13:42:29+00:00 Kevin Hao haokexin@gmail.com 2021-08-05T07:29:17+00:00 67c98e023135ff81b8d52998a6fdb8ca0c518d82 [ Upstream commit e5c6b312ce3cc97e90ea159446e6bfa06645364d ] The struct sugov_tunables is protected by the kobject, so we can't free it directly. Otherwise we would get a call trace like this: ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x30 WARNING: CPU: 3 PID: 720 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100 Modules linked in: CPU: 3 PID: 720 Comm: a.sh Tainted: G W 5.14.0-rc1-next-20210715-yocto-standard+ #507 Hardware name: Marvell OcteonTX CN96XX board (DT) pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--) pc : debug_print_object+0xb8/0x100 lr : debug_print_object+0xb8/0x100 sp : ffff80001ecaf910 x29: ffff80001ecaf910 x28: ffff00011b10b8d0 x27: ffff800011043d80 x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000 x23: ffff80001142aa68 x22: ffff800011043d80 x21: ffff00010de46f20 x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010 x17: 6e6968207473696c x16: 5f72656d6974203a x15: 6570797420746365 x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69 x11: ffff8000124b1560 x10: ffff800012331520 x9 : ffff8000100ca6b0 x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 0000000000000001 x5 : ffff800011d8c000 x4 : ffff800011d8c740 x3 : 0000000000000000 x2 : ffff0001108301c0 x1 : ab3c90eedf9c0f00 x0 : 0000000000000000 Call trace: debug_print_object+0xb8/0x100 __debug_check_no_obj_freed+0x1c0/0x230 debug_check_no_obj_freed+0x20/0x88 slab_free_freelist_hook+0x154/0x1c8 kfree+0x114/0x5d0 sugov_exit+0xbc/0xc0 cpufreq_exit_governor+0x44/0x90 cpufreq_set_policy+0x268/0x4a8 store_scaling_governor+0xe0/0x128 store+0xc0/0xf0 sysfs_kf_write+0x54/0x80 kernfs_fop_write_iter+0x128/0x1c0 new_sync_write+0xf0/0x190 vfs_write+0x2d4/0x478 ksys_write+0x74/0x100 __arm64_sys_write+0x24/0x30 invoke_syscall.constprop.0+0x54/0xe0 do_el0_svc+0x64/0x158 el0_svc+0x2c/0xb0 el0t_64_sync_handler+0xb0/0xb8 el0t_64_sync+0x198/0x19c irq event stamp: 5518 hardirqs last enabled at (5517): [<ffff8000100cbd7c>] console_unlock+0x554/0x6c8 hardirqs last disabled at (5518): [<ffff800010fc0638>] el1_dbg+0x28/0xa0 softirqs last enabled at (5504): [<ffff8000100106e0>] __do_softirq+0x4d0/0x6c0 softirqs last disabled at (5483): [<ffff800010049548>] irq_exit+0x1b0/0x1b8 So split the original sugov_tunables_free() into two functions, sugov_clear_global_tunables() is just used to clear the global_tunables and the new sugov_tunables_free() is used as kobj_type::release to release the sugov_tunables safely. Fixes: 9bdcb44e391d ("cpufreq: schedutil: New governor based on scheduler utilization data") Cc: 4.7+ <stable@vger.kernel.org> # 4.7+ Signed-off-by: Kevin Hao <haokexin@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e5c6b312ce3cc97e90ea159446e6bfa06645364d ]

The struct sugov_tunables is protected by the kobject, so we can't free
it directly. Otherwise we would get a call trace like this:
  ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x30
  WARNING: CPU: 3 PID: 720 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100
  Modules linked in:
  CPU: 3 PID: 720 Comm: a.sh Tainted: G        W         5.14.0-rc1-next-20210715-yocto-standard+ #507
  Hardware name: Marvell OcteonTX CN96XX board (DT)
  pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--)
  pc : debug_print_object+0xb8/0x100
  lr : debug_print_object+0xb8/0x100
  sp : ffff80001ecaf910
  x29: ffff80001ecaf910 x28: ffff00011b10b8d0 x27: ffff800011043d80
  x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000
  x23: ffff80001142aa68 x22: ffff800011043d80 x21: ffff00010de46f20
  x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010
  x17: 6e6968207473696c x16: 5f72656d6974203a x15: 6570797420746365
  x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69
  x11: ffff8000124b1560 x10: ffff800012331520 x9 : ffff8000100ca6b0
  x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 0000000000000001
  x5 : ffff800011d8c000 x4 : ffff800011d8c740 x3 : 0000000000000000
  x2 : ffff0001108301c0 x1 : ab3c90eedf9c0f00 x0 : 0000000000000000
  Call trace:
   debug_print_object+0xb8/0x100
   __debug_check_no_obj_freed+0x1c0/0x230
   debug_check_no_obj_freed+0x20/0x88
   slab_free_freelist_hook+0x154/0x1c8
   kfree+0x114/0x5d0
   sugov_exit+0xbc/0xc0
   cpufreq_exit_governor+0x44/0x90
   cpufreq_set_policy+0x268/0x4a8
   store_scaling_governor+0xe0/0x128
   store+0xc0/0xf0
   sysfs_kf_write+0x54/0x80
   kernfs_fop_write_iter+0x128/0x1c0
   new_sync_write+0xf0/0x190
   vfs_write+0x2d4/0x478
   ksys_write+0x74/0x100
   __arm64_sys_write+0x24/0x30
   invoke_syscall.constprop.0+0x54/0xe0
   do_el0_svc+0x64/0x158
   el0_svc+0x2c/0xb0
   el0t_64_sync_handler+0xb0/0xb8
   el0t_64_sync+0x198/0x19c
  irq event stamp: 5518
  hardirqs last  enabled at (5517): [<ffff8000100cbd7c>] console_unlock+0x554/0x6c8
  hardirqs last disabled at (5518): [<ffff800010fc0638>] el1_dbg+0x28/0xa0
  softirqs last  enabled at (5504): [<ffff8000100106e0>] __do_softirq+0x4d0/0x6c0
  softirqs last disabled at (5483): [<ffff800010049548>] irq_exit+0x1b0/0x1b8

So split the original sugov_tunables_free() into two functions,
sugov_clear_global_tunables() is just used to clear the global_tunables
and the new sugov_tunables_free() is used as kobj_type::release to
release the sugov_tunables safely.

Fixes: 9bdcb44e391d ("cpufreq: schedutil: New governor based on scheduler utilization data")
Cc: 4.7+ <stable@vger.kernel.org> # 4.7+
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Add oversize check before call kvcalloc() 2021-09-30T08:09:25+00:00 Bixuan Cui cuibixuan@huawei.com 2021-09-11T00:55:57+00:00 93937596e0652d50973f9dc944fea1694ac8cdfd [ Upstream commit 0e6491b559704da720f6da09dd0a52c4df44c514 ] Commit 7661809d493b ("mm: don't allow oversized kvmalloc() calls") add the oversize check. When the allocation is larger than what kmalloc() supports, the following warning triggered: WARNING: CPU: 0 PID: 8408 at mm/util.c:597 kvmalloc_node+0x108/0x110 mm/util.c:597 Modules linked in: CPU: 0 PID: 8408 Comm: syz-executor221 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvmalloc_node+0x108/0x110 mm/util.c:597 Call Trace: kvmalloc include/linux/mm.h:806 [inline] kvmalloc_array include/linux/mm.h:824 [inline] kvcalloc include/linux/mm.h:829 [inline] check_btf_line kernel/bpf/verifier.c:9925 [inline] check_btf_info kernel/bpf/verifier.c:10049 [inline] bpf_check+0xd634/0x150d0 kernel/bpf/verifier.c:13759 bpf_prog_load kernel/bpf/syscall.c:2301 [inline] __sys_bpf+0x11181/0x126e0 kernel/bpf/syscall.c:4587 __do_sys_bpf kernel/bpf/syscall.c:4691 [inline] __se_sys_bpf kernel/bpf/syscall.c:4689 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4689 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported-by: syzbot+f3e749d4c662818ae439@syzkaller.appspotmail.com Signed-off-by: Bixuan Cui <cuibixuan@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210911005557.45518-1-cuibixuan@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0e6491b559704da720f6da09dd0a52c4df44c514 ]

Commit 7661809d493b ("mm: don't allow oversized kvmalloc() calls") add the
oversize check. When the allocation is larger than what kmalloc() supports,
the following warning triggered:

WARNING: CPU: 0 PID: 8408 at mm/util.c:597 kvmalloc_node+0x108/0x110 mm/util.c:597
Modules linked in:
CPU: 0 PID: 8408 Comm: syz-executor221 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kvmalloc_node+0x108/0x110 mm/util.c:597
Call Trace:
 kvmalloc include/linux/mm.h:806 [inline]
 kvmalloc_array include/linux/mm.h:824 [inline]
 kvcalloc include/linux/mm.h:829 [inline]
 check_btf_line kernel/bpf/verifier.c:9925 [inline]
 check_btf_info kernel/bpf/verifier.c:10049 [inline]
 bpf_check+0xd634/0x150d0 kernel/bpf/verifier.c:13759
 bpf_prog_load kernel/bpf/syscall.c:2301 [inline]
 __sys_bpf+0x11181/0x126e0 kernel/bpf/syscall.c:4587
 __do_sys_bpf kernel/bpf/syscall.c:4691 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4689 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4689
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: syzbot+f3e749d4c662818ae439@syzkaller.appspotmail.com
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210911005557.45518-1-cuibixuan@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
blktrace: Fix uaf in blk_trace access after removing by sysfs 2021-09-30T08:09:24+00:00 Zhihao Cheng chengzhihao1@huawei.com 2021-09-23T13:49:21+00:00 ebb8d26d93c3ec3c7576c52a8373a2309423c069 [ Upstream commit 5afedf670caf30a2b5a52da96eb7eac7dee6a9c9 ] There is an use-after-free problem triggered by following process: P1(sda) P2(sdb) echo 0 > /sys/block/sdb/trace/enable blk_trace_remove_queue synchronize_rcu blk_trace_free relay_close rcu_read_lock __blk_add_trace trace_note_tsk (Iterate running_trace_list) relay_close_buf relay_destroy_buf kfree(buf) trace_note(sdb's bt) relay_reserve buf->offset <- nullptr deference (use-after-free) !!! rcu_read_unlock [ 502.714379] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 502.715260] #PF: supervisor read access in kernel mode [ 502.715903] #PF: error_code(0x0000) - not-present page [ 502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0 [ 502.717252] Oops: 0000 [#1] SMP [ 502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360 [ 502.732872] Call Trace: [ 502.733193] __blk_add_trace.cold+0x137/0x1a3 [ 502.733734] blk_add_trace_rq+0x7b/0xd0 [ 502.734207] blk_add_trace_rq_issue+0x54/0xa0 [ 502.734755] blk_mq_start_request+0xde/0x1b0 [ 502.735287] scsi_queue_rq+0x528/0x1140 ... [ 502.742704] sg_new_write.isra.0+0x16e/0x3e0 [ 502.747501] sg_ioctl+0x466/0x1100 Reproduce method: ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sda, BLKTRACESTART) ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sdb, BLKTRACESTART) echo 0 > /sys/block/sdb/trace/enable & // Add delay(mdelay/msleep) before kernel enters blk_trace_free() ioctl$SG_IO(/dev/sda, SG_IO, ...) // Enters trace_note_tsk() after blk_trace_free() returned // Use mdelay in rcu region rather than msleep(which may schedule out) Remove blk_trace from running_list before calling blk_trace_free() by sysfs if blk_trace is at Blktrace_running state. Fixes: c71a896154119f ("blktrace: add ftrace plugin") Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Link: https://lore.kernel.org/r/20210923134921.109194-1-chengzhihao1@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 5afedf670caf30a2b5a52da96eb7eac7dee6a9c9 ]

There is an use-after-free problem triggered by following process:

      P1(sda)				P2(sdb)
			echo 0 > /sys/block/sdb/trace/enable
			  blk_trace_remove_queue
			    synchronize_rcu
			    blk_trace_free
			      relay_close
rcu_read_lock
__blk_add_trace
  trace_note_tsk
  (Iterate running_trace_list)
			        relay_close_buf
				  relay_destroy_buf
				    kfree(buf)
    trace_note(sdb's bt)
      relay_reserve
        buf->offset <- nullptr deference (use-after-free) !!!
rcu_read_unlock

[  502.714379] BUG: kernel NULL pointer dereference, address:
0000000000000010
[  502.715260] #PF: supervisor read access in kernel mode
[  502.715903] #PF: error_code(0x0000) - not-present page
[  502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0
[  502.717252] Oops: 0000 [#1] SMP
[  502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360
[  502.732872] Call Trace:
[  502.733193]  __blk_add_trace.cold+0x137/0x1a3
[  502.733734]  blk_add_trace_rq+0x7b/0xd0
[  502.734207]  blk_add_trace_rq_issue+0x54/0xa0
[  502.734755]  blk_mq_start_request+0xde/0x1b0
[  502.735287]  scsi_queue_rq+0x528/0x1140
...
[  502.742704]  sg_new_write.isra.0+0x16e/0x3e0
[  502.747501]  sg_ioctl+0x466/0x1100

Reproduce method:
  ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
  ioctl(/dev/sda, BLKTRACESTART)
  ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
  ioctl(/dev/sdb, BLKTRACESTART)

  echo 0 > /sys/block/sdb/trace/enable &
  // Add delay(mdelay/msleep) before kernel enters blk_trace_free()

  ioctl$SG_IO(/dev/sda, SG_IO, ...)
  // Enters trace_note_tsk() after blk_trace_free() returned
  // Use mdelay in rcu region rather than msleep(which may schedule out)

Remove blk_trace from running_list before calling blk_trace_free() by
sysfs if blk_trace is at Blktrace_running state.

Fixes: c71a896154119f ("blktrace: add ftrace plugin")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20210923134921.109194-1-chengzhihao1@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
profiling: fix shift-out-of-bounds bugs 2021-09-26T12:07:09+00:00 Pavel Skripkin paskripkin@gmail.com 2021-09-08T02:58:21+00:00 b94def8a475ffc1a32f447db062bb2f0cf3e7125 commit 2d186afd04d669fe9c48b994c41a7405a3c9f16d upstream. Syzbot reported shift-out-of-bounds bug in profile_init(). The problem was in incorrect prof_shift. Since prof_shift value comes from userspace we need to clamp this value into [0, BITS_PER_LONG -1] boundaries. Second possible shiht-out-of-bounds was found by Tetsuo: sample_step local variable in read_profile() had "unsigned int" type, but prof_shift allows to make a BITS_PER_LONG shift. So, to prevent possible shiht-out-of-bounds sample_step type was changed to "unsigned long". Also, "unsigned short int" will be sufficient for storing [0, BITS_PER_LONG] value, that's why there is no need for "unsigned long" prof_shift. Link: https://lkml.kernel.org/r/20210813140022.5011-1-paskripkin@gmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+e68c89a9510c159d9684@syzkaller.appspotmail.com Suggested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2d186afd04d669fe9c48b994c41a7405a3c9f16d upstream.

Syzbot reported shift-out-of-bounds bug in profile_init().
The problem was in incorrect prof_shift. Since prof_shift value comes from
userspace we need to clamp this value into [0, BITS_PER_LONG -1]
boundaries.

Second possible shiht-out-of-bounds was found by Tetsuo:
sample_step local variable in read_profile() had "unsigned int" type,
but prof_shift allows to make a BITS_PER_LONG shift. So, to prevent
possible shiht-out-of-bounds sample_step type was changed to
"unsigned long".

Also, "unsigned short int" will be sufficient for storing
[0, BITS_PER_LONG] value, that's why there is no need for
"unsigned long" prof_shift.

Link: https://lkml.kernel.org/r/20210813140022.5011-1-paskripkin@gmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-and-tested-by: syzbot+e68c89a9510c159d9684@syzkaller.appspotmail.com
Suggested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
prctl: allow to setup brk for et_dyn executables 2021-09-26T12:07:08+00:00 Cyrill Gorcunov gorcunov@gmail.com 2021-09-08T03:00:41+00:00 5607b1bae1c852a794f777ee3a60eae981fcdb7d commit e1fbbd073137a9d63279f6bf363151a938347640 upstream. Keno Fischer reported that when a binray loaded via ld-linux-x the prctl(PR_SET_MM_MAP) doesn't allow to setup brk value because it lays before mm:end_data. For example a test program shows | # ~/t | | start_code 401000 | end_code 401a15 | start_stack 7ffce4577dd0 | start_data 403e10 | end_data 40408c | start_brk b5b000 | sbrk(0) b5b000 and when executed via ld-linux | # /lib64/ld-linux-x86-64.so.2 ~/t | | start_code 7fc25b0a4000 | end_code 7fc25b0c4524 | start_stack 7fffcc6b2400 | start_data 7fc25b0ce4c0 | end_data 7fc25b0cff98 | start_brk 55555710c000 | sbrk(0) 55555710c000 This of course prevent criu from restoring such programs. Looking into how kernel operates with brk/start_brk inside brk() syscall I don't see any problem if we allow to setup brk/start_brk without checking for end_data. Even if someone pass some weird address here on a purpose then the worst possible result will be an unexpected unmapping of existing vma (own vma, since prctl works with the callers memory) but test for RLIMIT_DATA is still valid and a user won't be able to gain more memory in case of expanding VMAs via new values shipped with prctl call. Link: https://lkml.kernel.org/r/20210121221207.GB2174@grain Fixes: bbdc6076d2e5 ("binfmt_elf: move brk out of mmap when doing direct loader exec") Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Reported-by: Keno Fischer <keno@juliacomputing.com> Acked-by: Andrey Vagin <avagin@gmail.com> Tested-by: Andrey Vagin <avagin@gmail.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e1fbbd073137a9d63279f6bf363151a938347640 upstream.

Keno Fischer reported that when a binray loaded via ld-linux-x the
prctl(PR_SET_MM_MAP) doesn't allow to setup brk value because it lays
before mm:end_data.

For example a test program shows

 | # ~/t
 |
 | start_code      401000
 | end_code        401a15
 | start_stack     7ffce4577dd0
 | start_data	   403e10
 | end_data        40408c
 | start_brk	   b5b000
 | sbrk(0)         b5b000

and when executed via ld-linux

 | # /lib64/ld-linux-x86-64.so.2 ~/t
 |
 | start_code      7fc25b0a4000
 | end_code        7fc25b0c4524
 | start_stack     7fffcc6b2400
 | start_data	   7fc25b0ce4c0
 | end_data        7fc25b0cff98
 | start_brk	   55555710c000
 | sbrk(0)         55555710c000

This of course prevent criu from restoring such programs.  Looking into
how kernel operates with brk/start_brk inside brk() syscall I don't see
any problem if we allow to setup brk/start_brk without checking for
end_data.  Even if someone pass some weird address here on a purpose then
the worst possible result will be an unexpected unmapping of existing vma
(own vma, since prctl works with the callers memory) but test for
RLIMIT_DATA is still valid and a user won't be able to gain more memory in
case of expanding VMAs via new values shipped with prctl call.

Link: https://lkml.kernel.org/r/20210121221207.GB2174@grain
Fixes: bbdc6076d2e5 ("binfmt_elf: move brk out of mmap when doing direct loader exec")
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reported-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Andrey Vagin <avagin@gmail.com>
Tested-by: Andrey Vagin <avagin@gmail.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing/probes: Reject events which have the same name of existing one 2021-09-22T10:26:43+00:00 Masami Hiramatsu mhiramat@kernel.org 2021-08-19T10:26:02+00:00 b3435cd96848da83708b417d68e37453b9c6915a [ Upstream commit 8e242060c6a4947e8ae7d29794af6a581db08841 ] Since kprobe_events and uprobe_events only check whether the other same-type probe event has the same name or not, if the user gives the same name of the existing tracepoint event (or the other type of probe events), it silently fails to create the tracefs entry (but registered.) as below. /sys/kernel/tracing # ls events/task/task_rename enable filter format hist id trigger /sys/kernel/tracing # echo p:task/task_rename vfs_read >> kprobe_events [ 113.048508] Could not create tracefs 'task_rename' directory /sys/kernel/tracing # cat kprobe_events p:task/task_rename vfs_read To fix this issue, check whether the existing events have the same name or not in trace_probe_register_event_call(). If exists, it rejects to register the new event. Link: https://lkml.kernel.org/r/162936876189.187130.17558311387542061930.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8e242060c6a4947e8ae7d29794af6a581db08841 ]

Since kprobe_events and uprobe_events only check whether the
other same-type probe event has the same name or not, if the
user gives the same name of the existing tracepoint event (or
the other type of probe events), it silently fails to create
the tracefs entry (but registered.) as below.

/sys/kernel/tracing # ls events/task/task_rename
enable   filter   format   hist     id       trigger
/sys/kernel/tracing # echo p:task/task_rename vfs_read >> kprobe_events
[  113.048508] Could not create tracefs 'task_rename' directory
/sys/kernel/tracing # cat kprobe_events
p:task/task_rename vfs_read

To fix this issue, check whether the existing events have the
same name or not in trace_probe_register_event_call(). If exists,
it rejects to register the new event.

Link: https://lkml.kernel.org/r/162936876189.187130.17558311387542061930.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>