The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5ebcbe342b1c12fae44b4f83cbeae1520e09857e Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm(a)xmission.com>
Date: Sat, 16 Oct 2021 12:17:30 -0500
Subject: [PATCH] ucounts: Move get_ucounts from cred_alloc_blank to
key_change_session_keyring
Setting cred->ucounts in cred_alloc_blank does not make sense. The
uid and user_ns are deliberately not set in cred_alloc_blank but
instead the setting is delayed until key_change_session_keyring.
So move dealing with ucounts into key_change_session_keyring as well.
Unfortunately that movement of get_ucounts adds a new failure mode to
key_change_session_keyring. I do not see anything stopping the parent
process from calling setuid and changing the relevant part of it's
cred while keyctl_session_to_parent is running making it fundamentally
necessary to call get_ucounts in key_change_session_keyring. Which
means that the new failure mode cannot be avoided.
A failure of key_change_session_keyring results in a single threaded
parent keeping it's existing credentials. Which results in the parent
process not being able to access the session keyring and whichever
keys are in the new keyring.
Further get_ucounts is only expected to fail if the number of bits in
the refernece count for the structure is too few.
Since the code has no other way to report the failure of get_ucounts
and because such failures are not expected to be common add a WARN_ONCE
to report this problem to userspace.
Between the WARN_ONCE and the parent process not having access to
the keys in the new session keyring I expect any failure of get_ucounts
will be noticed and reported and we can find another way to handle this
condition. (Possibly by just making ucounts->count an atomic_long_t).
Cc: stable(a)vger.kernel.org
Fixes: 905ae01c4ae2 ("Add a reference to ucounts for each cred")
Link: https://lkml.kernel.org/r/7k0ias0uf.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao(a)google.com>
Reviewed-by: Alexey Gladkov <legion(a)kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm(a)xmission.com>
diff --git a/kernel/cred.c b/kernel/cred.c
index 16c05dfbec4d..1ae0b4948a5a 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -225,8 +225,6 @@ struct cred *cred_alloc_blank(void)
#ifdef CONFIG_DEBUG_CREDENTIALS
new->magic = CRED_MAGIC;
#endif
- new->ucounts = get_ucounts(&init_ucounts);
-
if (security_cred_alloc_blank(new, GFP_KERNEL_ACCOUNT) < 0)
goto error;
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index e3d79a7b6db6..b5d5333ab330 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -918,6 +918,13 @@ void key_change_session_keyring(struct callback_head *twork)
return;
}
+ /* If get_ucounts fails more bits are needed in the refcount */
+ if (unlikely(!get_ucounts(old->ucounts))) {
+ WARN_ONCE(1, "In %s get_ucounts failed\n", __func__);
+ put_cred(new);
+ return;
+ }
+
new-> uid = old-> uid;
new-> euid = old-> euid;
new-> suid = old-> suid;
@@ -927,6 +934,7 @@ void key_change_session_keyring(struct callback_head *twork)
new-> sgid = old-> sgid;
new->fsgid = old->fsgid;
new->user = get_uid(old->user);
+ new->ucounts = old->ucounts;
new->user_ns = get_user_ns(old->user_ns);
new->group_info = get_group_info(old->group_info);
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From ed65df63a39a3f6ed04f7258de8b6789e5021c18 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Mon, 18 Oct 2021 15:44:12 -0400
Subject: [PATCH] tracing: Have all levels of checks prevent recursion
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.alib…
Link: https://lkml.kernel.org/r/20211018154412.09fcad3c@gandalf.local.home
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley(a)hansenpartnership.com>
Cc: Helge Deller <deller(a)gmx.de>
Cc: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh(a)kernel.crashing.org>
Cc: Paul Mackerras <paulus(a)samba.org>
Cc: Paul Walmsley <paul.walmsley(a)sifive.com>
Cc: Palmer Dabbelt <palmer(a)dabbelt.com>
Cc: Albert Ou <aou(a)eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Colin Ian King <colin.king(a)canonical.com>
Cc: Masami Hiramatsu <mhiramat(a)kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz(a)infradead.org>
Cc: Nicholas Piggin <npiggin(a)gmail.com>
Cc: Jisheng Zhang <jszhang(a)kernel.org>
Cc: =?utf-8?b?546L6LSH?= <yun.wang(a)linux.alibaba.com>
Cc: Guo Ren <guoren(a)kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/include/linux/trace_recursion.h b/include/linux/trace_recursion.h
index a9f9c5714e65..fe95f0922526 100644
--- a/include/linux/trace_recursion.h
+++ b/include/linux/trace_recursion.h
@@ -16,23 +16,8 @@
* When function tracing occurs, the following steps are made:
* If arch does not support a ftrace feature:
* call internal function (uses INTERNAL bits) which calls...
- * If callback is registered to the "global" list, the list
- * function is called and recursion checks the GLOBAL bits.
- * then this function calls...
* The function callback, which can use the FTRACE bits to
* check for recursion.
- *
- * Now if the arch does not support a feature, and it calls
- * the global list function which calls the ftrace callback
- * all three of these steps will do a recursion protection.
- * There's no reason to do one if the previous caller already
- * did. The recursion that we are protecting against will
- * go through the same steps again.
- *
- * To prevent the multiple recursion checks, if a recursion
- * bit is set that is higher than the MAX bit of the current
- * check, then we know that the check was made by the previous
- * caller, and we can skip the current check.
*/
enum {
/* Function recursion bits */
@@ -40,12 +25,14 @@ enum {
TRACE_FTRACE_NMI_BIT,
TRACE_FTRACE_IRQ_BIT,
TRACE_FTRACE_SIRQ_BIT,
+ TRACE_FTRACE_TRANSITION_BIT,
- /* INTERNAL_BITs must be greater than FTRACE_BITs */
+ /* Internal use recursion bits */
TRACE_INTERNAL_BIT,
TRACE_INTERNAL_NMI_BIT,
TRACE_INTERNAL_IRQ_BIT,
TRACE_INTERNAL_SIRQ_BIT,
+ TRACE_INTERNAL_TRANSITION_BIT,
TRACE_BRANCH_BIT,
/*
@@ -86,12 +73,6 @@ enum {
*/
TRACE_GRAPH_NOTRACE_BIT,
- /*
- * When transitioning between context, the preempt_count() may
- * not be correct. Allow for a single recursion to cover this case.
- */
- TRACE_TRANSITION_BIT,
-
/* Used to prevent recursion recording from recursing. */
TRACE_RECORD_RECURSION_BIT,
};
@@ -113,12 +94,10 @@ enum {
#define TRACE_CONTEXT_BITS 4
#define TRACE_FTRACE_START TRACE_FTRACE_BIT
-#define TRACE_FTRACE_MAX ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
#define TRACE_LIST_START TRACE_INTERNAL_BIT
-#define TRACE_LIST_MAX ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
-#define TRACE_CONTEXT_MASK TRACE_LIST_MAX
+#define TRACE_CONTEXT_MASK ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
/*
* Used for setting context
@@ -132,6 +111,7 @@ enum {
TRACE_CTX_IRQ,
TRACE_CTX_SOFTIRQ,
TRACE_CTX_NORMAL,
+ TRACE_CTX_TRANSITION,
};
static __always_inline int trace_get_context_bit(void)
@@ -160,45 +140,34 @@ extern void ftrace_record_recursion(unsigned long ip, unsigned long parent_ip);
#endif
static __always_inline int trace_test_and_set_recursion(unsigned long ip, unsigned long pip,
- int start, int max)
+ int start)
{
unsigned int val = READ_ONCE(current->trace_recursion);
int bit;
- /* A previous recursion check was made */
- if ((val & TRACE_CONTEXT_MASK) > max)
- return 0;
-
bit = trace_get_context_bit() + start;
if (unlikely(val & (1 << bit))) {
/*
* It could be that preempt_count has not been updated during
* a switch between contexts. Allow for a single recursion.
*/
- bit = TRACE_TRANSITION_BIT;
+ bit = TRACE_CTX_TRANSITION + start;
if (val & (1 << bit)) {
do_ftrace_record_recursion(ip, pip);
return -1;
}
- } else {
- /* Normal check passed, clear the transition to allow it again */
- val &= ~(1 << TRACE_TRANSITION_BIT);
}
val |= 1 << bit;
current->trace_recursion = val;
barrier();
- return bit + 1;
+ return bit;
}
static __always_inline void trace_clear_recursion(int bit)
{
- if (!bit)
- return;
-
barrier();
- bit--;
trace_recursion_clear(bit);
}
@@ -214,7 +183,7 @@ static __always_inline void trace_clear_recursion(int bit)
static __always_inline int ftrace_test_recursion_trylock(unsigned long ip,
unsigned long parent_ip)
{
- return trace_test_and_set_recursion(ip, parent_ip, TRACE_FTRACE_START, TRACE_FTRACE_MAX);
+ return trace_test_and_set_recursion(ip, parent_ip, TRACE_FTRACE_START);
}
/**
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7efbc8aaf7f6..635fbdc9d589 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6977,7 +6977,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op;
int bit;
- bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX);
+ bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
if (bit < 0)
return;
@@ -7052,7 +7052,7 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
{
int bit;
- bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX);
+ bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
if (bit < 0)
return;
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From ed65df63a39a3f6ed04f7258de8b6789e5021c18 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Mon, 18 Oct 2021 15:44:12 -0400
Subject: [PATCH] tracing: Have all levels of checks prevent recursion
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.alib…
Link: https://lkml.kernel.org/r/20211018154412.09fcad3c@gandalf.local.home
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley(a)hansenpartnership.com>
Cc: Helge Deller <deller(a)gmx.de>
Cc: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh(a)kernel.crashing.org>
Cc: Paul Mackerras <paulus(a)samba.org>
Cc: Paul Walmsley <paul.walmsley(a)sifive.com>
Cc: Palmer Dabbelt <palmer(a)dabbelt.com>
Cc: Albert Ou <aou(a)eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Colin Ian King <colin.king(a)canonical.com>
Cc: Masami Hiramatsu <mhiramat(a)kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz(a)infradead.org>
Cc: Nicholas Piggin <npiggin(a)gmail.com>
Cc: Jisheng Zhang <jszhang(a)kernel.org>
Cc: =?utf-8?b?546L6LSH?= <yun.wang(a)linux.alibaba.com>
Cc: Guo Ren <guoren(a)kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/include/linux/trace_recursion.h b/include/linux/trace_recursion.h
index a9f9c5714e65..fe95f0922526 100644
--- a/include/linux/trace_recursion.h
+++ b/include/linux/trace_recursion.h
@@ -16,23 +16,8 @@
* When function tracing occurs, the following steps are made:
* If arch does not support a ftrace feature:
* call internal function (uses INTERNAL bits) which calls...
- * If callback is registered to the "global" list, the list
- * function is called and recursion checks the GLOBAL bits.
- * then this function calls...
* The function callback, which can use the FTRACE bits to
* check for recursion.
- *
- * Now if the arch does not support a feature, and it calls
- * the global list function which calls the ftrace callback
- * all three of these steps will do a recursion protection.
- * There's no reason to do one if the previous caller already
- * did. The recursion that we are protecting against will
- * go through the same steps again.
- *
- * To prevent the multiple recursion checks, if a recursion
- * bit is set that is higher than the MAX bit of the current
- * check, then we know that the check was made by the previous
- * caller, and we can skip the current check.
*/
enum {
/* Function recursion bits */
@@ -40,12 +25,14 @@ enum {
TRACE_FTRACE_NMI_BIT,
TRACE_FTRACE_IRQ_BIT,
TRACE_FTRACE_SIRQ_BIT,
+ TRACE_FTRACE_TRANSITION_BIT,
- /* INTERNAL_BITs must be greater than FTRACE_BITs */
+ /* Internal use recursion bits */
TRACE_INTERNAL_BIT,
TRACE_INTERNAL_NMI_BIT,
TRACE_INTERNAL_IRQ_BIT,
TRACE_INTERNAL_SIRQ_BIT,
+ TRACE_INTERNAL_TRANSITION_BIT,
TRACE_BRANCH_BIT,
/*
@@ -86,12 +73,6 @@ enum {
*/
TRACE_GRAPH_NOTRACE_BIT,
- /*
- * When transitioning between context, the preempt_count() may
- * not be correct. Allow for a single recursion to cover this case.
- */
- TRACE_TRANSITION_BIT,
-
/* Used to prevent recursion recording from recursing. */
TRACE_RECORD_RECURSION_BIT,
};
@@ -113,12 +94,10 @@ enum {
#define TRACE_CONTEXT_BITS 4
#define TRACE_FTRACE_START TRACE_FTRACE_BIT
-#define TRACE_FTRACE_MAX ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
#define TRACE_LIST_START TRACE_INTERNAL_BIT
-#define TRACE_LIST_MAX ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
-#define TRACE_CONTEXT_MASK TRACE_LIST_MAX
+#define TRACE_CONTEXT_MASK ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
/*
* Used for setting context
@@ -132,6 +111,7 @@ enum {
TRACE_CTX_IRQ,
TRACE_CTX_SOFTIRQ,
TRACE_CTX_NORMAL,
+ TRACE_CTX_TRANSITION,
};
static __always_inline int trace_get_context_bit(void)
@@ -160,45 +140,34 @@ extern void ftrace_record_recursion(unsigned long ip, unsigned long parent_ip);
#endif
static __always_inline int trace_test_and_set_recursion(unsigned long ip, unsigned long pip,
- int start, int max)
+ int start)
{
unsigned int val = READ_ONCE(current->trace_recursion);
int bit;
- /* A previous recursion check was made */
- if ((val & TRACE_CONTEXT_MASK) > max)
- return 0;
-
bit = trace_get_context_bit() + start;
if (unlikely(val & (1 << bit))) {
/*
* It could be that preempt_count has not been updated during
* a switch between contexts. Allow for a single recursion.
*/
- bit = TRACE_TRANSITION_BIT;
+ bit = TRACE_CTX_TRANSITION + start;
if (val & (1 << bit)) {
do_ftrace_record_recursion(ip, pip);
return -1;
}
- } else {
- /* Normal check passed, clear the transition to allow it again */
- val &= ~(1 << TRACE_TRANSITION_BIT);
}
val |= 1 << bit;
current->trace_recursion = val;
barrier();
- return bit + 1;
+ return bit;
}
static __always_inline void trace_clear_recursion(int bit)
{
- if (!bit)
- return;
-
barrier();
- bit--;
trace_recursion_clear(bit);
}
@@ -214,7 +183,7 @@ static __always_inline void trace_clear_recursion(int bit)
static __always_inline int ftrace_test_recursion_trylock(unsigned long ip,
unsigned long parent_ip)
{
- return trace_test_and_set_recursion(ip, parent_ip, TRACE_FTRACE_START, TRACE_FTRACE_MAX);
+ return trace_test_and_set_recursion(ip, parent_ip, TRACE_FTRACE_START);
}
/**
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7efbc8aaf7f6..635fbdc9d589 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6977,7 +6977,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op;
int bit;
- bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX);
+ bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
if (bit < 0)
return;
@@ -7052,7 +7052,7 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
{
int bit;
- bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX);
+ bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START);
if (bit < 0)
return;
The patch below does not apply to the 5.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From bc28368596436e6e81ffc48c815b8225d96121c0 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com>
Date: Fri, 15 Oct 2021 19:12:21 +0200
Subject: [PATCH] ACPI: PM: Do not turn off power resources in unknown state
Commit 6381195ad7d0 ("ACPI: power: Rework turning off unused power
resources") caused power resources in unknown state with reference
counters equal to zero to be turned off too, but that caused issues
to appear in the field, so modify the code to only turn off power
resources that are known to be "on".
Link: https://lore.kernel.org/linux-acpi/6faf4b92-78d5-47a4-63df-cc2bab7769d0@mol…
Fixes: 6381195ad7d0 ("ACPI: power: Rework turning off unused power resources")
Reported-by: Andreas K. Huettel <andreas.huettel(a)ur.de>
Tested-by: Andreas K. Huettel <andreas.huettel(a)ur.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Cc: 5.14+ <stable(a)vger.kernel.org> # 5.14+
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index b9863e22b952..f0ed4414edb1 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -1035,13 +1035,8 @@ void acpi_turn_off_unused_power_resources(void)
list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
mutex_lock(&resource->resource_lock);
- /*
- * Turn off power resources in an unknown state too, because the
- * platform firmware on some system expects the OS to turn off
- * power resources without any users unconditionally.
- */
if (!resource->ref_count &&
- resource->state != ACPI_POWER_RESOURCE_STATE_OFF) {
+ resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
acpi_handle_debug(resource->device.handle, "Turning OFF\n");
__acpi_power_off(resource);
}
This is a note to let you know that I've just added the patch titled
iio: buffer: Fix memory leak in iio_buffers_alloc_sysfs_and_mask()
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 486a25084155bf633768c26f022201c051d6fd95 Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang(a)huawei.com>
Date: Mon, 18 Oct 2021 14:37:18 +0800
Subject: iio: buffer: Fix memory leak in iio_buffers_alloc_sysfs_and_mask()
When 'iio_dev_opaque->buffer_ioctl_handler' alloc fails in
iio_buffers_alloc_sysfs_and_mask(), the 'attrs' allocated in
iio_buffer_register_legacy_sysfs_groups() will be leaked:
unreferenced object 0xffff888108568d00 (size 128):
comm "88", pid 2014, jiffies 4294963294 (age 26.920s)
hex dump (first 32 bytes):
80 3e da 02 80 88 ff ff 00 3a da 02 80 88 ff ff .>.......:......
00 35 da 02 80 88 ff ff 00 38 da 02 80 88 ff ff .5.......8......
backtrace:
[<0000000095a9e51e>] __kmalloc+0x1a3/0x2f0
[<00000000faa3735e>] iio_buffers_alloc_sysfs_and_mask+0xfa3/0x1480 [industrialio]
[<00000000a46384dc>] __iio_device_register+0x52e/0x1b40 [industrialio]
[<00000000210af05e>] __devm_iio_device_register+0x22/0x80 [industrialio]
[<00000000730d7b41>] adjd_s311_probe+0x195/0x200 [adjd_s311]
[<00000000c0f70eb9>] i2c_device_probe+0xa07/0xbb0
The iio_buffer_register_legacy_sysfs_groups() is
called in __iio_buffer_alloc_sysfs_and_mask(),
so move the iio_buffer_unregister_legacy_sysfs_groups()
into __iio_buffer_free_sysfs_and_mask(), then the memory
will be freed.
Reported-by: Hulk Robot <hulkci(a)huawei.com>
Fixes: d9a625744ed0 ("iio: core: merge buffer/ & scan_elements/ attributes")
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
Link: https://lore.kernel.org/r/20211018063718.1971240-1-yangyingliang@huawei.com
Cc: <Stable(a)vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com>
---
drivers/iio/industrialio-buffer.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 1c3972150ab4..2f98ba70e3d7 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1587,8 +1587,12 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
return ret;
}
-static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer)
+static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer,
+ struct iio_dev *indio_dev,
+ int index)
{
+ if (index == 0)
+ iio_buffer_unregister_legacy_sysfs_groups(indio_dev);
bitmap_free(buffer->scan_mask);
kfree(buffer->buffer_group.name);
kfree(buffer->buffer_group.attrs);
@@ -1642,7 +1646,7 @@ int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
error_unwind_sysfs_and_mask:
for (; unwind_idx >= 0; unwind_idx--) {
buffer = iio_dev_opaque->attached_buffers[unwind_idx];
- __iio_buffer_free_sysfs_and_mask(buffer);
+ __iio_buffer_free_sysfs_and_mask(buffer, indio_dev, unwind_idx);
}
return ret;
}
@@ -1659,11 +1663,9 @@ void iio_buffers_free_sysfs_and_mask(struct iio_dev *indio_dev)
iio_device_ioctl_handler_unregister(iio_dev_opaque->buffer_ioctl_handler);
kfree(iio_dev_opaque->buffer_ioctl_handler);
- iio_buffer_unregister_legacy_sysfs_groups(indio_dev);
-
for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) {
buffer = iio_dev_opaque->attached_buffers[i];
- __iio_buffer_free_sysfs_and_mask(buffer);
+ __iio_buffer_free_sysfs_and_mask(buffer, indio_dev, i);
}
}
--
2.33.1
This is a note to let you know that I've just added the patch titled
iio: core: fix double free in iio_device_unregister_sysfs()
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 19833c40d0415d6fe4340b5b9c46239abbf718f6 Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang(a)huawei.com>
Date: Wed, 13 Oct 2021 11:05:32 +0800
Subject: iio: core: fix double free in iio_device_unregister_sysfs()
I got the double free report:
BUG: KASAN: double-free or invalid-free in kfree+0xce/0x390
iio_device_unregister_sysfs+0x108/0x13b [industrialio]
iio_dev_release+0x9e/0x10e [industrialio]
device_release+0xa5/0x240
If __iio_device_register() fails, iio_dev_opaque->groups will be freed
in error path in iio_device_unregister_sysfs(), then iio_dev_release()
will call iio_device_unregister_sysfs() again, it causes double free.
Set iio_dev_opaque->groups to NULL when it's freed to fix this double free.
Not this is a local work around for a more general mess around life time
management that will get cleaned up and should make this handling
unnecesarry.
Fixes: 32f171724e5c ("iio: core: rework iio device group creation")
Reported-by: Hulk Robot <hulkci(a)huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex(a)gmail.com>
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
Link: https://lore.kernel.org/r/20211013030532.956133-1-yangyingliang@huawei.com
Cc: <Stable(a)vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com>
---
drivers/iio/industrialio-core.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 48fda6a79076..3e1e86d987cc 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1600,6 +1600,7 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
kfree(iio_dev_opaque->chan_attr_group.attrs);
iio_dev_opaque->chan_attr_group.attrs = NULL;
kfree(iio_dev_opaque->groups);
+ iio_dev_opaque->groups = NULL;
}
static void iio_dev_release(struct device *device)
--
2.33.1
This is a note to let you know that I've just added the patch titled
iio: adc: tsc2046: fix scan interval warning
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 69b31fd7a61784692db6433c05d46915b1b1a680 Mon Sep 17 00:00:00 2001
From: Oleksij Rempel <o.rempel(a)pengutronix.de>
Date: Thu, 7 Oct 2021 11:30:06 +0200
Subject: iio: adc: tsc2046: fix scan interval warning
Sync if statement with the actual warning.
Fixes: 9504db5765e8 ("iio: adc: tsc2046: fix a warning message in tsc2046_adc_update_scan_mode()")
Signed-off-by: Oleksij Rempel <o.rempel(a)pengutronix.de>
Link: https://lore.kernel.org/r/20211007093007.1466-2-o.rempel@pengutronix.de
Cc: <Stable(a)vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com>
---
drivers/iio/adc/ti-tsc2046.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iio/adc/ti-tsc2046.c b/drivers/iio/adc/ti-tsc2046.c
index 170950d5dd49..d84ae6b008c1 100644
--- a/drivers/iio/adc/ti-tsc2046.c
+++ b/drivers/iio/adc/ti-tsc2046.c
@@ -398,7 +398,7 @@ static int tsc2046_adc_update_scan_mode(struct iio_dev *indio_dev,
priv->xfer.len = size;
priv->time_per_scan_us = size * 8 * priv->time_per_bit_ns / NSEC_PER_USEC;
- if (priv->scan_interval_us > priv->time_per_scan_us)
+ if (priv->scan_interval_us < priv->time_per_scan_us)
dev_warn(&priv->spi->dev, "The scan interval (%d) is less then calculated scan time (%d)\n",
priv->scan_interval_us, priv->time_per_scan_us);
--
2.33.1
This is a note to let you know that I've just added the patch titled
iio: buffer: Fix memory leak in
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 604faf9a2ecd1addcc0c10a47e5aaef3c4d4fd6b Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang(a)huawei.com>
Date: Wed, 13 Oct 2021 22:42:42 +0800
Subject: iio: buffer: Fix memory leak in
iio_buffer_register_legacy_sysfs_groups()
If the second iio_device_register_sysfs_group() fails,
'legacy_buffer_group.attrs' need be freed too or it will
cause memory leak:
unreferenced object 0xffff888003618280 (size 64):
comm "xrun", pid 357, jiffies 4294907259 (age 22.296s)
hex dump (first 32 bytes):
80 f6 8c 03 80 88 ff ff 80 fb 8c 03 80 88 ff ff ................
00 f9 8c 03 80 88 ff ff 80 fc 8c 03 80 88 ff ff ................
backtrace:
[<00000000076bfd43>] __kmalloc+0x1a3/0x2f0
[<00000000c32e4886>] iio_buffers_alloc_sysfs_and_mask+0xc31/0x1290 [industrialio]
Reported-by: Hulk Robot <hulkci(a)huawei.com>
Fixes: d9a625744ed0 ("iio: core: merge buffer/ & scan_elements/ attributes")
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
Link: https://lore.kernel.org/r/20211013144242.1685060-1-yangyingliang@huawei.com
Cc: <Stable(a)vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com>
---
drivers/iio/industrialio-buffer.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index ae0912a14578..1c3972150ab4 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1367,10 +1367,10 @@ static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,
return 0;
-error_free_buffer_attrs:
- kfree(iio_dev_opaque->legacy_buffer_group.attrs);
error_free_scan_el_attrs:
kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
+error_free_buffer_attrs:
+ kfree(iio_dev_opaque->legacy_buffer_group.attrs);
return ret;
}
--
2.33.1
This is a note to let you know that I've just added the patch titled
iio: core: check return value when calling dev_set_name()
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From fe6f45f6ba22d625a8500cbad0237c60dd3117ee Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang(a)huawei.com>
Date: Tue, 12 Oct 2021 14:36:24 +0800
Subject: iio: core: check return value when calling dev_set_name()
I got a null-ptr-deref report when doing fault injection test:
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:strlen+0x0/0x20
Call Trace:
start_creating+0x199/0x2f0
debugfs_create_dir+0x25/0x430
__iio_device_register+0x4da/0x1b40 [industrialio]
__devm_iio_device_register+0x22/0x80 [industrialio]
max1027_probe+0x639/0x860 [max1027]
spi_probe+0x183/0x210
really_probe+0x285/0xc30
If dev_set_name() fails, the dev_name() is null, check the return
value of dev_set_name() to avoid the null-ptr-deref.
Reported-by: Hulk Robot <hulkci(a)huawei.com>
Fixes: e553f182d55b ("staging: iio: core: Introduce debugfs support...")
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
Cc: <Stable(a)vger.kernel.org>
Link: https://lore.kernel.org/r/20211012063624.3167460-1-yangyingliang@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com>
---
drivers/iio/industrialio-core.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 2dbb37e09b8c..48fda6a79076 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1664,7 +1664,13 @@ struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
kfree(iio_dev_opaque);
return NULL;
}
- dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id);
+
+ if (dev_set_name(&indio_dev->dev, "iio:device%d", iio_dev_opaque->id)) {
+ ida_simple_remove(&iio_ida, iio_dev_opaque->id);
+ kfree(iio_dev_opaque);
+ return NULL;
+ }
+
INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
INIT_LIST_HEAD(&iio_dev_opaque->ioctl_handlers);
--
2.33.1
This is a note to let you know that I've just added the patch titled
iio: buffer: check return value of kstrdup_const()
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 2c0ad3f0cc04dec489552a21b80cd6d708bea96d Mon Sep 17 00:00:00 2001
From: Yang Yingliang <yangyingliang(a)huawei.com>
Date: Wed, 13 Oct 2021 12:04:38 +0800
Subject: iio: buffer: check return value of kstrdup_const()
Check return value of kstrdup_const() in iio_buffer_wrap_attr(),
or it will cause null-ptr-deref in kernfs_name_hash() when calling
device_add() as follows:
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:strlen+0x0/0x20
Call Trace:
kernfs_name_hash+0x22/0x110
kernfs_find_ns+0x11d/0x390
kernfs_remove_by_name_ns+0x3b/0xb0
remove_files.isra.1+0x7b/0x190
internal_create_group+0x7f1/0xbb0
internal_create_groups+0xa3/0x150
device_add+0x8f0/0x2020
cdev_device_add+0xc3/0x160
__iio_device_register+0x1427/0x1b40 [industrialio]
__devm_iio_device_register+0x22/0x80 [industrialio]
adjd_s311_probe+0x195/0x200 [adjd_s311]
i2c_device_probe+0xa07/0xbb0
Reported-by: Hulk Robot <hulkci(a)huawei.com>
Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
Link: https://lore.kernel.org/r/20211013040438.1689277-1-yangyingliang@huawei.com
Cc: <Stable(a)vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com>
---
drivers/iio/industrialio-buffer.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index a95cc2da56be..55802da1deee 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1312,6 +1312,11 @@ static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer,
iio_attr->buffer = buffer;
memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr));
iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL);
+ if (!iio_attr->dev_attr.attr.name) {
+ kfree(iio_attr);
+ return NULL;
+ }
+
sysfs_attr_init(&iio_attr->dev_attr.attr);
list_add(&iio_attr->l, &buffer->buffer_attr_list);
--
2.33.1