The patch below does not apply to the 4.19-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 5ae5fbd2107959b68ac69a8b75412208663aea88 Mon Sep 17 00:00:00 2001
From: Athira Rajeev <atrajeev(a)linux.vnet.ibm.com>
Date: Thu, 25 Feb 2021 05:10:39 -0500
Subject: [PATCH] powerpc/perf: Fix handling of privilege level checks in perf
interrupt context
Running "perf mem record" in powerpc platforms with selinux enabled
resulted in soft lockup's. Below call-trace was seen in the logs:
CPU: 58 PID: 3751 Comm: sssd_nss Not tainted 5.11.0-rc7+ #2
NIP: c000000000dff3d4 LR: c000000000dff3d0 CTR: 0000000000000000
REGS: c000007fffab7d60 TRAP: 0100 Not tainted (5.11.0-rc7+)
...
NIP _raw_spin_lock_irqsave+0x94/0x120
LR _raw_spin_lock_irqsave+0x90/0x120
Call Trace:
0xc00000000fd47260 (unreliable)
skb_queue_tail+0x3c/0x90
audit_log_end+0x6c/0x180
common_lsm_audit+0xb0/0xe0
slow_avc_audit+0xa4/0x110
avc_has_perm+0x1c4/0x260
selinux_perf_event_open+0x74/0xd0
security_perf_event_open+0x68/0xc0
record_and_restart+0x6e8/0x7f0
perf_event_interrupt+0x22c/0x560
performance_monitor_exception0x4c/0x60
performance_monitor_common_virt+0x1c8/0x1d0
interrupt: f00 at _raw_spin_lock_irqsave+0x38/0x120
NIP: c000000000dff378 LR: c000000000b5fbbc CTR: c0000000007d47f0
REGS: c00000000fd47860 TRAP: 0f00 Not tainted (5.11.0-rc7+)
...
NIP _raw_spin_lock_irqsave+0x38/0x120
LR skb_queue_tail+0x3c/0x90
interrupt: f00
0x38 (unreliable)
0xc00000000aae6200
audit_log_end+0x6c/0x180
audit_log_exit+0x344/0xf80
__audit_syscall_exit+0x2c0/0x320
do_syscall_trace_leave+0x148/0x200
syscall_exit_prepare+0x324/0x390
system_call_common+0xfc/0x27c
The above trace shows that while the CPU was handling a performance
monitor exception, there was a call to security_perf_event_open()
function. In powerpc core-book3s, this function is called from
perf_allow_kernel() check during recording of data address in the
sample via perf_get_data_addr().
Commit da97e18458fb ("perf_event: Add support for LSM and SELinux
checks") introduced security enhancements to perf. As part of this
commit, the new security hook for perf_event_open() was added in all
places where perf paranoid check was previously used. In powerpc
core-book3s code, originally had paranoid checks in
perf_get_data_addr() and power_pmu_bhrb_read(). So
perf_paranoid_kernel() checks were replaced with perf_allow_kernel()
in these PMU helper functions as well.
The intention of paranoid checks in core-book3s was to verify
privilege access before capturing some of the sample data. Along with
paranoid checks, perf_allow_kernel() also does a
security_perf_event_open(). Since these functions are accessed while
recording a sample, we end up calling selinux_perf_event_open() in PMI
context. Some of the security functions use spinlock like
sidtab_sid2str_put(). If a perf interrupt hits under a spin lock and
if we end up in calling selinux hook functions in PMI handler, this
could cause a dead lock.
Since the purpose of this security hook is to control access to
perf_event_open(), it is not right to call this in interrupt context.
The paranoid checks in powerpc core-book3s were done at interrupt time
which is also not correct.
Reference commits:
Commit cd1231d7035f ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()")
Commit bb19af816025 ("powerpc/perf: Prevent kernel address leak to userspace via BHRB buffer")
We only allow creation of events that have already passed the
privilege checks in perf_event_open(). So these paranoid checks are
not needed at event time. As a fix, patch uses
'event->attr.exclude_kernel' check to prevent exposing kernel address
for userspace only sampling.
Fixes: cd1231d7035f ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()")
Cc: stable(a)vger.kernel.org # v4.17+
Suggested-by: Michael Ellerman <mpe(a)ellerman.id.au>
Signed-off-by: Athira Rajeev <atrajeev(a)linux.vnet.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/1614247839-1428-1-git-send-email-atrajeev@linux.v…
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 6817331e22ff..766f064f00fb 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -222,7 +222,7 @@ static inline void perf_get_data_addr(struct perf_event *event, struct pt_regs *
if (!(mmcra & MMCRA_SAMPLE_ENABLE) || sdar_valid)
*addrp = mfspr(SPRN_SDAR);
- if (is_kernel_addr(mfspr(SPRN_SDAR)) && perf_allow_kernel(&event->attr) != 0)
+ if (is_kernel_addr(mfspr(SPRN_SDAR)) && event->attr.exclude_kernel)
*addrp = 0;
}
@@ -507,7 +507,7 @@ static void power_pmu_bhrb_read(struct perf_event *event, struct cpu_hw_events *
* addresses, hence include a check before filtering code
*/
if (!(ppmu->flags & PPMU_ARCH_31) &&
- is_kernel_addr(addr) && perf_allow_kernel(&event->attr) != 0)
+ is_kernel_addr(addr) && event->attr.exclude_kernel)
continue;
/* Branches are read most recent first (ie. mfbhrb 0 is
The patch below does not apply to the 5.4-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 5ae5fbd2107959b68ac69a8b75412208663aea88 Mon Sep 17 00:00:00 2001
From: Athira Rajeev <atrajeev(a)linux.vnet.ibm.com>
Date: Thu, 25 Feb 2021 05:10:39 -0500
Subject: [PATCH] powerpc/perf: Fix handling of privilege level checks in perf
interrupt context
Running "perf mem record" in powerpc platforms with selinux enabled
resulted in soft lockup's. Below call-trace was seen in the logs:
CPU: 58 PID: 3751 Comm: sssd_nss Not tainted 5.11.0-rc7+ #2
NIP: c000000000dff3d4 LR: c000000000dff3d0 CTR: 0000000000000000
REGS: c000007fffab7d60 TRAP: 0100 Not tainted (5.11.0-rc7+)
...
NIP _raw_spin_lock_irqsave+0x94/0x120
LR _raw_spin_lock_irqsave+0x90/0x120
Call Trace:
0xc00000000fd47260 (unreliable)
skb_queue_tail+0x3c/0x90
audit_log_end+0x6c/0x180
common_lsm_audit+0xb0/0xe0
slow_avc_audit+0xa4/0x110
avc_has_perm+0x1c4/0x260
selinux_perf_event_open+0x74/0xd0
security_perf_event_open+0x68/0xc0
record_and_restart+0x6e8/0x7f0
perf_event_interrupt+0x22c/0x560
performance_monitor_exception0x4c/0x60
performance_monitor_common_virt+0x1c8/0x1d0
interrupt: f00 at _raw_spin_lock_irqsave+0x38/0x120
NIP: c000000000dff378 LR: c000000000b5fbbc CTR: c0000000007d47f0
REGS: c00000000fd47860 TRAP: 0f00 Not tainted (5.11.0-rc7+)
...
NIP _raw_spin_lock_irqsave+0x38/0x120
LR skb_queue_tail+0x3c/0x90
interrupt: f00
0x38 (unreliable)
0xc00000000aae6200
audit_log_end+0x6c/0x180
audit_log_exit+0x344/0xf80
__audit_syscall_exit+0x2c0/0x320
do_syscall_trace_leave+0x148/0x200
syscall_exit_prepare+0x324/0x390
system_call_common+0xfc/0x27c
The above trace shows that while the CPU was handling a performance
monitor exception, there was a call to security_perf_event_open()
function. In powerpc core-book3s, this function is called from
perf_allow_kernel() check during recording of data address in the
sample via perf_get_data_addr().
Commit da97e18458fb ("perf_event: Add support for LSM and SELinux
checks") introduced security enhancements to perf. As part of this
commit, the new security hook for perf_event_open() was added in all
places where perf paranoid check was previously used. In powerpc
core-book3s code, originally had paranoid checks in
perf_get_data_addr() and power_pmu_bhrb_read(). So
perf_paranoid_kernel() checks were replaced with perf_allow_kernel()
in these PMU helper functions as well.
The intention of paranoid checks in core-book3s was to verify
privilege access before capturing some of the sample data. Along with
paranoid checks, perf_allow_kernel() also does a
security_perf_event_open(). Since these functions are accessed while
recording a sample, we end up calling selinux_perf_event_open() in PMI
context. Some of the security functions use spinlock like
sidtab_sid2str_put(). If a perf interrupt hits under a spin lock and
if we end up in calling selinux hook functions in PMI handler, this
could cause a dead lock.
Since the purpose of this security hook is to control access to
perf_event_open(), it is not right to call this in interrupt context.
The paranoid checks in powerpc core-book3s were done at interrupt time
which is also not correct.
Reference commits:
Commit cd1231d7035f ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()")
Commit bb19af816025 ("powerpc/perf: Prevent kernel address leak to userspace via BHRB buffer")
We only allow creation of events that have already passed the
privilege checks in perf_event_open(). So these paranoid checks are
not needed at event time. As a fix, patch uses
'event->attr.exclude_kernel' check to prevent exposing kernel address
for userspace only sampling.
Fixes: cd1231d7035f ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()")
Cc: stable(a)vger.kernel.org # v4.17+
Suggested-by: Michael Ellerman <mpe(a)ellerman.id.au>
Signed-off-by: Athira Rajeev <atrajeev(a)linux.vnet.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/1614247839-1428-1-git-send-email-atrajeev@linux.v…
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 6817331e22ff..766f064f00fb 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -222,7 +222,7 @@ static inline void perf_get_data_addr(struct perf_event *event, struct pt_regs *
if (!(mmcra & MMCRA_SAMPLE_ENABLE) || sdar_valid)
*addrp = mfspr(SPRN_SDAR);
- if (is_kernel_addr(mfspr(SPRN_SDAR)) && perf_allow_kernel(&event->attr) != 0)
+ if (is_kernel_addr(mfspr(SPRN_SDAR)) && event->attr.exclude_kernel)
*addrp = 0;
}
@@ -507,7 +507,7 @@ static void power_pmu_bhrb_read(struct perf_event *event, struct cpu_hw_events *
* addresses, hence include a check before filtering code
*/
if (!(ppmu->flags & PPMU_ARCH_31) &&
- is_kernel_addr(addr) && perf_allow_kernel(&event->attr) != 0)
+ is_kernel_addr(addr) && event->attr.exclude_kernel)
continue;
/* Branches are read most recent first (ie. mfbhrb 0 is
The patch below does not apply to the 5.4-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 c119565a15a628efdfa51352f9f6c5186e506a1c Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy(a)csgroup.eu>
Date: Mon, 1 Feb 2021 06:29:50 +0000
Subject: [PATCH] powerpc/603: Fix protection of user pages mapped with
PROT_NONE
On book3s/32, page protection is defined by the PP bits in the PTE
which provide the following protection depending on the access
keys defined in the matching segment register:
- PP 00 means RW with key 0 and N/A with key 1.
- PP 01 means RW with key 0 and RO with key 1.
- PP 10 means RW with both key 0 and key 1.
- PP 11 means RO with both key 0 and key 1.
Since the implementation of kernel userspace access protection,
PP bits have been set as follows:
- PP00 for pages without _PAGE_USER
- PP01 for pages with _PAGE_USER and _PAGE_RW
- PP11 for pages with _PAGE_USER and without _PAGE_RW
For kernelspace segments, kernel accesses are performed with key 0
and user accesses are performed with key 1. As PP00 is used for
non _PAGE_USER pages, user can't access kernel pages not flagged
_PAGE_USER while kernel can.
For userspace segments, both kernel and user accesses are performed
with key 0, therefore pages not flagged _PAGE_USER are still
accessible to the user.
This shouldn't be an issue, because userspace is expected to be
accessible to the user. But unlike most other architectures, powerpc
implements PROT_NONE protection by removing _PAGE_USER flag instead of
flagging the page as not valid. This means that pages in userspace
that are not flagged _PAGE_USER shall remain inaccessible.
To get the expected behaviour, just mimic other architectures in the
TLB miss handler by checking _PAGE_USER permission on userspace
accesses as if it was the _PAGE_PRESENT bit.
Note that this problem only is only for 603 cores. The 604+ have
an hash table, and hash_page() function already implement the
verification of _PAGE_USER permission on userspace pages.
Fixes: f342adca3afc ("powerpc/32s: Prepare Kernel Userspace Access Protection")
Cc: stable(a)vger.kernel.org # v5.2+
Reported-by: Christoph Plattner <christoph.plattner(a)thalesgroup.com>
Signed-off-by: Christophe Leroy <christophe.leroy(a)csgroup.eu>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/4a0c6e3bb8f0c162457bf54d9bc6fd8d7b55129f.16121609…
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 727fdab557c9..565e84e20a72 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -457,11 +457,12 @@ InstructionTLBMiss:
cmplw 0,r1,r3
#endif
mfspr r2, SPRN_SDR1
- li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+ li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC | _PAGE_USER
rlwinm r2, r2, 28, 0xfffff000
#ifdef CONFIG_MODULES
bgt- 112f
lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
+ li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
#endif
112: rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
@@ -520,10 +521,11 @@ DataLoadTLBMiss:
lis r1, TASK_SIZE@h /* check if kernel address */
cmplw 0,r1,r3
mfspr r2, SPRN_SDR1
- li r1, _PAGE_PRESENT | _PAGE_ACCESSED
+ li r1, _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER
rlwinm r2, r2, 28, 0xfffff000
bgt- 112f
lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
+ li r1, _PAGE_PRESENT | _PAGE_ACCESSED
addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
112: rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
lwz r2,0(r2) /* get pmd entry */
@@ -597,10 +599,11 @@ DataStoreTLBMiss:
lis r1, TASK_SIZE@h /* check if kernel address */
cmplw 0,r1,r3
mfspr r2, SPRN_SDR1
- li r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED
+ li r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER
rlwinm r2, r2, 28, 0xfffff000
bgt- 112f
lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
+ li r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED
addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
112: rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
lwz r2,0(r2) /* get pmd entry */
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 c119565a15a628efdfa51352f9f6c5186e506a1c Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy(a)csgroup.eu>
Date: Mon, 1 Feb 2021 06:29:50 +0000
Subject: [PATCH] powerpc/603: Fix protection of user pages mapped with
PROT_NONE
On book3s/32, page protection is defined by the PP bits in the PTE
which provide the following protection depending on the access
keys defined in the matching segment register:
- PP 00 means RW with key 0 and N/A with key 1.
- PP 01 means RW with key 0 and RO with key 1.
- PP 10 means RW with both key 0 and key 1.
- PP 11 means RO with both key 0 and key 1.
Since the implementation of kernel userspace access protection,
PP bits have been set as follows:
- PP00 for pages without _PAGE_USER
- PP01 for pages with _PAGE_USER and _PAGE_RW
- PP11 for pages with _PAGE_USER and without _PAGE_RW
For kernelspace segments, kernel accesses are performed with key 0
and user accesses are performed with key 1. As PP00 is used for
non _PAGE_USER pages, user can't access kernel pages not flagged
_PAGE_USER while kernel can.
For userspace segments, both kernel and user accesses are performed
with key 0, therefore pages not flagged _PAGE_USER are still
accessible to the user.
This shouldn't be an issue, because userspace is expected to be
accessible to the user. But unlike most other architectures, powerpc
implements PROT_NONE protection by removing _PAGE_USER flag instead of
flagging the page as not valid. This means that pages in userspace
that are not flagged _PAGE_USER shall remain inaccessible.
To get the expected behaviour, just mimic other architectures in the
TLB miss handler by checking _PAGE_USER permission on userspace
accesses as if it was the _PAGE_PRESENT bit.
Note that this problem only is only for 603 cores. The 604+ have
an hash table, and hash_page() function already implement the
verification of _PAGE_USER permission on userspace pages.
Fixes: f342adca3afc ("powerpc/32s: Prepare Kernel Userspace Access Protection")
Cc: stable(a)vger.kernel.org # v5.2+
Reported-by: Christoph Plattner <christoph.plattner(a)thalesgroup.com>
Signed-off-by: Christophe Leroy <christophe.leroy(a)csgroup.eu>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/4a0c6e3bb8f0c162457bf54d9bc6fd8d7b55129f.16121609…
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 727fdab557c9..565e84e20a72 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -457,11 +457,12 @@ InstructionTLBMiss:
cmplw 0,r1,r3
#endif
mfspr r2, SPRN_SDR1
- li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+ li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC | _PAGE_USER
rlwinm r2, r2, 28, 0xfffff000
#ifdef CONFIG_MODULES
bgt- 112f
lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
+ li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
#endif
112: rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
@@ -520,10 +521,11 @@ DataLoadTLBMiss:
lis r1, TASK_SIZE@h /* check if kernel address */
cmplw 0,r1,r3
mfspr r2, SPRN_SDR1
- li r1, _PAGE_PRESENT | _PAGE_ACCESSED
+ li r1, _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER
rlwinm r2, r2, 28, 0xfffff000
bgt- 112f
lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
+ li r1, _PAGE_PRESENT | _PAGE_ACCESSED
addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
112: rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
lwz r2,0(r2) /* get pmd entry */
@@ -597,10 +599,11 @@ DataStoreTLBMiss:
lis r1, TASK_SIZE@h /* check if kernel address */
cmplw 0,r1,r3
mfspr r2, SPRN_SDR1
- li r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED
+ li r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER
rlwinm r2, r2, 28, 0xfffff000
bgt- 112f
lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */
+ li r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED
addi r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */
112: rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
lwz r2,0(r2) /* get pmd entry */
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 cf25ef6b631c6fc6c0435fc91eba8734cca20511 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption
Make sure to hold the gpio_lock when removing the gpio device from the
gpio_devices list (when dropping the last reference) to avoid corrupting
the list when there are concurrent accesses.
Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
Cc: stable(a)vger.kernel.org # 4.6
Reviewed-by: Saravana Kannan <saravanak(a)google.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski(a)baylibre.com>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6e0572515d02..4253837f870b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+ unsigned long flags;
+ spin_lock_irqsave(&gpio_lock, flags);
list_del(&gdev->list);
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
ida_free(&gpio_ida, gdev->id);
kfree_const(gdev->label);
kfree(gdev->descs);
The patch below does not apply to the 4.19-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 cf25ef6b631c6fc6c0435fc91eba8734cca20511 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption
Make sure to hold the gpio_lock when removing the gpio device from the
gpio_devices list (when dropping the last reference) to avoid corrupting
the list when there are concurrent accesses.
Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
Cc: stable(a)vger.kernel.org # 4.6
Reviewed-by: Saravana Kannan <saravanak(a)google.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski(a)baylibre.com>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6e0572515d02..4253837f870b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+ unsigned long flags;
+ spin_lock_irqsave(&gpio_lock, flags);
list_del(&gdev->list);
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
ida_free(&gpio_ida, gdev->id);
kfree_const(gdev->label);
kfree(gdev->descs);
The patch below does not apply to the 5.4-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 cf25ef6b631c6fc6c0435fc91eba8734cca20511 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption
Make sure to hold the gpio_lock when removing the gpio device from the
gpio_devices list (when dropping the last reference) to avoid corrupting
the list when there are concurrent accesses.
Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
Cc: stable(a)vger.kernel.org # 4.6
Reviewed-by: Saravana Kannan <saravanak(a)google.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski(a)baylibre.com>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6e0572515d02..4253837f870b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+ unsigned long flags;
+ spin_lock_irqsave(&gpio_lock, flags);
list_del(&gdev->list);
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
ida_free(&gpio_ida, gdev->id);
kfree_const(gdev->label);
kfree(gdev->descs);
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 cf25ef6b631c6fc6c0435fc91eba8734cca20511 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption
Make sure to hold the gpio_lock when removing the gpio device from the
gpio_devices list (when dropping the last reference) to avoid corrupting
the list when there are concurrent accesses.
Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
Cc: stable(a)vger.kernel.org # 4.6
Reviewed-by: Saravana Kannan <saravanak(a)google.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski(a)baylibre.com>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6e0572515d02..4253837f870b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+ unsigned long flags;
+ spin_lock_irqsave(&gpio_lock, flags);
list_del(&gdev->list);
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
ida_free(&gpio_ida, gdev->id);
kfree_const(gdev->label);
kfree(gdev->descs);
The patch below does not apply to the 4.9-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 cf25ef6b631c6fc6c0435fc91eba8734cca20511 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Mon, 1 Mar 2021 10:05:19 +0100
Subject: [PATCH] gpio: fix gpio-device list corruption
Make sure to hold the gpio_lock when removing the gpio device from the
gpio_devices list (when dropping the last reference) to avoid corrupting
the list when there are concurrent accesses.
Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
Cc: stable(a)vger.kernel.org # 4.6
Reviewed-by: Saravana Kannan <saravanak(a)google.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski(a)baylibre.com>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6e0572515d02..4253837f870b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+ unsigned long flags;
+ spin_lock_irqsave(&gpio_lock, flags);
list_del(&gdev->list);
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
ida_free(&gpio_ida, gdev->id);
kfree_const(gdev->label);
kfree(gdev->descs);