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ARM: keystone: fix platform_domain_notifier array overrun

PATCH New Russell King 3 participants 3 messages May 10, 2018 – May 14, 2018

Subsystems (3)
Arm (32-bit) Arm sub-architectures Arm/Texas instrument Keystone architecture
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Russell King

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#0 lore raw

PATCH 1/1 ARM: keystone: fix platform_domain_notifier array overrun

platform_domain_notifier contains a variable sized array, which the pm_clk_notify() notifier treats as a NULL terminated array:

     for (con_id = clknb->con_ids; *con_id; con_id++)
             pm_clk_add(dev, *con_id);

Omitting the initialiser for con_ids means that the array is zero sized, and there is no NULL terminator. This leads to pm_clk_notify() overrunning into what ever structure follows, which may not be NULL. This leads to an oops:

Unable to handle kernel NULL pointer dereference at virtual address 0000008c
pgd = c0003000
[0000008c] *pgd=80000800004003c, *pmd=00000000c
Internal error: Oops: 206 [#1] PREEMPT SMP ARM
Modules linked in:c
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0+ #9
Hardware name: Keystone
PC is at strlen+0x0/0x34
LR is at kstrdup+0x18/0x54
pc : [<c0623340>]    lr : [<c0111d6c>]    psr: 20000013

sp : eec73dc0 ip : eed780c0 fp : 00000001
r10: 00000000 r9 : 00000000 r8 : eed71e10
r7 : 0000008c r6 : 0000008c r5 : 014000c0 r4 : c03a6ff4 r3 : c09445d0 r2 : 00000000 r1 : 014000c0 r0 : 0000008c
Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 30c5387d Table: 00003000 DAC: fffffffd Process swapper/0 (pid: 1, stack limit = 0xeec72210)

Stack: (0xeec73dc0 to 0xeec74000)

...
[<c0623340>] (strlen) from [<c0111d6c>] (kstrdup+0x18/0x54)
[<c0111d6c>] (kstrdup) from [<c03a6ff4>] (__pm_clk_add+0x58/0x120)
[<c03a6ff4>] (__pm_clk_add) from [<c03a731c>] (pm_clk_notify+0x64/0xa8)
[<c03a731c>] (pm_clk_notify) from [<c004614c>] (notifier_call_chain+0x44/0x84) [<c004614c>] (notifier_call_chain) from [<c0046320>] (__blocking_notifier_call_chain+0x48/0x60) [<c0046320>] (__blocking_notifier_call_chain) from [<c0046350>] (blocking_notifier_call_chain+0x18/0x20) [<c0046350>] (blocking_notifier_call_chain) from [<c0390234>] (device_add+0x36c/0x534) [<c0390234>] (device_add) from [<c047fc00>] (of_platform_device_create_pdata+0x70/0xa4) [<c047fc00>] (of_platform_device_create_pdata) from [<c047fea0>] (of_platform_bus_create+0xf0/0x1ec) [<c047fea0>] (of_platform_bus_create) from [<c047fff8>] (of_platform_populate+0x5c/0xac) [<c047fff8>] (of_platform_populate) from [<c08b1f04>] (of_platform_default_populate_init+0x8c/0xa8) [<c08b1f04>] (of_platform_default_populate_init) from [<c000a78c>] (do_one_initcall+0x3c/0x164) [<c000a78c>] (do_one_initcall) from [<c087bd9c>] (kernel_init_freeable+0x10c/0x1d0) [<c087bd9c>] (kernel_init_freeable) from [<c0628db0>] (kernel_init+0x8/0xf0) [<c0628db0>] (kernel_init) from [<c00090d8>] (ret_from_fork+0x14/0x3c)

Exception stack(0xeec73fb0 to 0xeec73ff8)
3fa0:                                     00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e3520000 1afffff7 e12fff1e c0801730 (e5d02000)
---[ end trace cafa8f148e262e80 ]---

Fix this by adding the necessary initialiser.

Fixes fc20ffe1213b ("ARM: keystone: add PM domain support for clock management")
Signed-off-by Russell King <[email protected]>

---
This looks to be a latent bug that's been present since the above commit - whether it's a problem depends on the data structure that the linker places after platform_domain_notifier - if the first word of the following structure is NULL, then the bug will be hidden. If it's a pointer to a string, or something that reasonably looks like a string, the bug will be hidden. If it's a value that points at an invalid memory address, then an oops similar to the above will result.

 arch/arm/mach-keystone/pm_domain.c | 1 +
 1 file changed, 1 insertion(+)
arch/arm/mach-keystone/pm_domain.c +1 -0
index fe57e2692629..abca83d22ff3 100644
@@ -29,6 +29,7 @@ static struct dev_pm_domain keystone_pm_domain = {
 
 static struct pm_clk_notifier_block platform_domain_notifier = {
 	.pm_domain = &keystone_pm_domain,
+	.con_ids = { NULL },
 };
 
 static const struct of_device_id of_keystone_table[] = {
Signature · 1 line
2.7.4
#1 lore raw

PATCH 1/1 ARM: keystone: fix platform_domain_notifier array overrun

Quoted 52 lines · Russell King

platform_domain_notifier contains a variable sized array, which the pm_clk_notify() notifier treats as a NULL terminated array:

      for (con_id = clknb->con_ids; *con_id; con_id++)
              pm_clk_add(dev, *con_id);

Omitting the initialiser for con_ids means that the array is zero sized, and there is no NULL terminator. This leads to pm_clk_notify() overrunning into what ever structure follows, which may not be NULL. This leads to an oops:

Unable to handle kernel NULL pointer dereference at virtual address 0000008c
pgd = c0003000
[0000008c] *pgd=80000800004003c, *pmd=00000000c
Internal error: Oops: 206 [#1] PREEMPT SMP ARM
Modules linked in:c
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0+ #9
Hardware name: Keystone
PC is at strlen+0x0/0x34
LR is at kstrdup+0x18/0x54
pc : [<c0623340>]    lr : [<c0111d6c>]    psr: 20000013

sp : eec73dc0 ip : eed780c0 fp : 00000001
r10: 00000000 r9 : 00000000 r8 : eed71e10
r7 : 0000008c r6 : 0000008c r5 : 014000c0 r4 : c03a6ff4 r3 : c09445d0 r2 : 00000000 r1 : 014000c0 r0 : 0000008c
Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 30c5387d Table: 00003000 DAC: fffffffd Process swapper/0 (pid: 1, stack limit = 0xeec72210)

Stack: (0xeec73dc0 to 0xeec74000)

...
[<c0623340>] (strlen) from [<c0111d6c>] (kstrdup+0x18/0x54)
[<c0111d6c>] (kstrdup) from [<c03a6ff4>] (__pm_clk_add+0x58/0x120)
[<c03a6ff4>] (__pm_clk_add) from [<c03a731c>] (pm_clk_notify+0x64/0xa8)
[<c03a731c>] (pm_clk_notify) from [<c004614c>] (notifier_call_chain+0x44/0x84) [<c004614c>] (notifier_call_chain) from [<c0046320>] (__blocking_notifier_call_chain+0x48/0x60) [<c0046320>] (__blocking_notifier_call_chain) from [<c0046350>] (blocking_notifier_call_chain+0x18/0x20) [<c0046350>] (blocking_notifier_call_chain) from [<c0390234>] (device_add+0x36c/0x534) [<c0390234>] (device_add) from [<c047fc00>] (of_platform_device_create_pdata+0x70/0xa4) [<c047fc00>] (of_platform_device_create_pdata) from [<c047fea0>] (of_platform_bus_create+0xf0/0x1ec) [<c047fea0>] (of_platform_bus_create) from [<c047fff8>] (of_platform_populate+0x5c/0xac) [<c047fff8>] (of_platform_populate) from [<c08b1f04>] (of_platform_default_populate_init+0x8c/0xa8) [<c08b1f04>] (of_platform_default_populate_init) from [<c000a78c>] (do_one_initcall+0x3c/0x164) [<c000a78c>] (do_one_initcall) from [<c087bd9c>] (kernel_init_freeable+0x10c/0x1d0) [<c087bd9c>] (kernel_init_freeable) from [<c0628db0>] (kernel_init+0x8/0xf0) [<c0628db0>] (kernel_init) from [<c00090d8>] (ret_from_fork+0x14/0x3c)

Exception stack(0xeec73fb0 to 0xeec73ff8)
3fa0:                                     00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e3520000 1afffff7 e12fff1e c0801730 (e5d02000)
---[ end trace cafa8f148e262e80 ]---
Quoted 5 lines

Fix this by adding the necessary initialiser.

Fixes fc20ffe1213b ("ARM: keystone: add PM domain support for clock management")
Signed-off-by Russell King <[email protected]>

---

Looks good. Thanks Russell !!

Acked-by Santosh Shilimkar <[email protected]>

Arnd, olof,
Could you please pick this up for the fixes branch ?

Applied
#2 lore raw

PATCH 1/1 ARM: keystone: fix platform_domain_notifier array overrun

Quoted 55 lines · Santosh Shilimkar
Quoted 54 lines · Russell King

platform_domain_notifier contains a variable sized array, which the pm_clk_notify() notifier treats as a NULL terminated array:

      for (con_id = clknb->con_ids; *con_id; con_id++)
              pm_clk_add(dev, *con_id);

Omitting the initialiser for con_ids means that the array is zero sized, and there is no NULL terminator. This leads to pm_clk_notify() overrunning into what ever structure follows, which may not be NULL. This leads to an oops:

Unable to handle kernel NULL pointer dereference at virtual address 0000008c
pgd = c0003000
[0000008c] *pgd=80000800004003c, *pmd=00000000c
Internal error: Oops: 206 [#1] PREEMPT SMP ARM
Modules linked in:c
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0+ #9
Hardware name: Keystone
PC is at strlen+0x0/0x34
LR is at kstrdup+0x18/0x54
pc : [<c0623340>]    lr : [<c0111d6c>]    psr: 20000013

sp : eec73dc0 ip : eed780c0 fp : 00000001
r10: 00000000 r9 : 00000000 r8 : eed71e10
r7 : 0000008c r6 : 0000008c r5 : 014000c0 r4 : c03a6ff4 r3 : c09445d0 r2 : 00000000 r1 : 014000c0 r0 : 0000008c
Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 30c5387d Table: 00003000 DAC: fffffffd Process swapper/0 (pid: 1, stack limit = 0xeec72210)

Stack: (0xeec73dc0 to 0xeec74000)

...
[<c0623340>] (strlen) from [<c0111d6c>] (kstrdup+0x18/0x54)
[<c0111d6c>] (kstrdup) from [<c03a6ff4>] (__pm_clk_add+0x58/0x120)
[<c03a6ff4>] (__pm_clk_add) from [<c03a731c>] (pm_clk_notify+0x64/0xa8)
[<c03a731c>] (pm_clk_notify) from [<c004614c>] (notifier_call_chain+0x44/0x84) [<c004614c>] (notifier_call_chain) from [<c0046320>] (__blocking_notifier_call_chain+0x48/0x60) [<c0046320>] (__blocking_notifier_call_chain) from [<c0046350>] (blocking_notifier_call_chain+0x18/0x20) [<c0046350>] (blocking_notifier_call_chain) from [<c0390234>] (device_add+0x36c/0x534) [<c0390234>] (device_add) from [<c047fc00>] (of_platform_device_create_pdata+0x70/0xa4) [<c047fc00>] (of_platform_device_create_pdata) from [<c047fea0>] (of_platform_bus_create+0xf0/0x1ec) [<c047fea0>] (of_platform_bus_create) from [<c047fff8>] (of_platform_populate+0x5c/0xac) [<c047fff8>] (of_platform_populate) from [<c08b1f04>] (of_platform_default_populate_init+0x8c/0xa8) [<c08b1f04>] (of_platform_default_populate_init) from [<c000a78c>] (do_one_initcall+0x3c/0x164) [<c000a78c>] (do_one_initcall) from [<c087bd9c>] (kernel_init_freeable+0x10c/0x1d0) [<c087bd9c>] (kernel_init_freeable) from [<c0628db0>] (kernel_init+0x8/0xf0) [<c0628db0>] (kernel_init) from [<c00090d8>] (ret_from_fork+0x14/0x3c)

Exception stack(0xeec73fb0 to 0xeec73ff8)
3fa0:                                     00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e3520000 1afffff7 e12fff1e c0801730 (e5d02000)
---[ end trace cafa8f148e262e80 ]---

Fix this by adding the necessary initialiser.

Quoted 8 lines
Quoted 3 lines
Fixes fc20ffe1213b ("ARM: keystone: add PM domain support for clock management")
Signed-off-by Russell King <[email protected]>

---

Looks good. Thanks Russell !!

Acked-by Santosh Shilimkar <[email protected]>

Arnd, olof,
Could you please pick this up for the fixes branch ?

Applied to fixes. Thanks!

-Olof