If spi_register_master fails in spi_bitbang_start
because device_add failure, We should return the
error code other than 0, otherwise calling
spi_bitbang_stop may trigger NULL pointer dereference
like this:
BUG: KASAN: null-ptr-deref in __list_del_entry_valid+0x45/0xd0
Read of size 8 at addr 0000000000000000 by task syz-executor.0/3661
CPU: 0 PID: 3661 Comm: syz-executor.0 Not tainted 5.1.0+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
dump_stack+0xa9/0x10e
? __list_del_entry_valid+0x45/0xd0
? __list_del_entry_valid+0x45/0xd0
__kasan_report+0x171/0x18d
? __list_del_entry_valid+0x45/0xd0
kasan_report+0xe/0x20
__list_del_entry_valid+0x45/0xd0
spi_unregister_controller+0x99/0x1b0
spi_lm70llp_attach+0x3ae/0x4b0 [spi_lm70llp]
? 0xffffffffc1128000
? klist_next+0x131/0x1e0
? driver_detach+0x40/0x40 [parport]
port_check+0x3b/0x50 [parport]
bus_for_each_dev+0x115/0x180
? subsys_dev_iter_exit+0x20/0x20
__parport_register_driver+0x1f0/0x210 [parport]
? 0xffffffffc1150000
do_one_initcall+0xb9/0x3b5
? perf_trace_initcall_level+0x270/0x270
? kasan_unpoison_shadow+0x30/0x40
? kasan_unpoison_shadow+0x30/0x40
do_init_module+0xe0/0x330
load_module+0x38eb/0x4270
? module_frob_arch_sections+0x20/0x20
? kernel_read_file+0x188/0x3f0
? find_held_lock+0x6d/0xd0
? fput_many+0x1a/0xe0
? __do_sys_finit_module+0x162/0x190
__do_sys_finit_module+0x162/0x190
? __ia32_sys_init_module+0x40/0x40
? __mutex_unlock_slowpath+0xb4/0x3f0
? wait_for_completion+0x240/0x240
? vfs_write+0x160/0x2a0
? lockdep_hardirqs_off+0xb5/0x100
? mark_held_locks+0x1a/0x90
? do_syscall_64+0x14/0x2a0
do_syscall_64+0x72/0x2a0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reported-by: Hulk Robot <[email protected]>
Fixes: 702a4879ec33 ("spi: bitbang: Let spi_bitbang_start() take a reference to master")
Signed-off-by: YueHaibing <[email protected]>
---
drivers/spi/spi-bitbang.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index dd9a8c54..be95be4 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -403,7 +403,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
if (ret)
spi_master_put(master);
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(spi_bitbang_start);
--
1.8.3.1
On Thu, May 16, 2019 at 9:57 AM YueHaibing <[email protected]> wrote:
> If spi_register_master fails in spi_bitbang_start
> because device_add failure, We should return the
> error code other than 0, otherwise calling
> spi_bitbang_stop may trigger NULL pointer dereference
> like this:
>
> BUG: KASAN: null-ptr-deref in __list_del_entry_valid+0x45/0xd0
> Read of size 8 at addr 0000000000000000 by task syz-executor.0/3661
[...]
> Reported-by: Hulk Robot <[email protected]>
> Fixes: 702a4879ec33 ("spi: bitbang: Let spi_bitbang_start() take a reference to master")
> Signed-off-by: YueHaibing <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
YueHaibing <[email protected]> 於 2019年5月16日 週四 下午3:57寫道：
>
> If spi_register_master fails in spi_bitbang_start
> because device_add failure, We should return the
> error code other than 0, otherwise calling
> spi_bitbang_stop may trigger NULL pointer dereference
> like this:
Reviewed-by: Axel Lin <[email protected]>
On 5/16/2019 1:26 PM, YueHaibing wrote:
> If spi_register_master fails in spi_bitbang_start
> because device_add failure, We should return the
> error code other than 0, otherwise calling
> spi_bitbang_stop may trigger NULL pointer dereference
> like this:
>
> BUG: KASAN: null-ptr-deref in __list_del_entry_valid+0x45/0xd0
> Read of size 8 at addr 0000000000000000 by task syz-executor.0/3661
>
> CPU: 0 PID: 3661 Comm: syz-executor.0 Not tainted 5.1.0+ #28
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
> Call Trace:
> dump_stack+0xa9/0x10e
> ? __list_del_entry_valid+0x45/0xd0
> ? __list_del_entry_valid+0x45/0xd0
> __kasan_report+0x171/0x18d
> ? __list_del_entry_valid+0x45/0xd0
> kasan_report+0xe/0x20
> __list_del_entry_valid+0x45/0xd0
> spi_unregister_controller+0x99/0x1b0
> spi_lm70llp_attach+0x3ae/0x4b0 [spi_lm70llp]
> ? 0xffffffffc1128000
> ? klist_next+0x131/0x1e0
> ? driver_detach+0x40/0x40 [parport]
> port_check+0x3b/0x50 [parport]
> bus_for_each_dev+0x115/0x180
> ? subsys_dev_iter_exit+0x20/0x20
> __parport_register_driver+0x1f0/0x210 [parport]
> ? 0xffffffffc1150000
> do_one_initcall+0xb9/0x3b5
> ? perf_trace_initcall_level+0x270/0x270
> ? kasan_unpoison_shadow+0x30/0x40
> ? kasan_unpoison_shadow+0x30/0x40
> do_init_module+0xe0/0x330
> load_module+0x38eb/0x4270
> ? module_frob_arch_sections+0x20/0x20
> ? kernel_read_file+0x188/0x3f0
> ? find_held_lock+0x6d/0xd0
> ? fput_many+0x1a/0xe0
> ? __do_sys_finit_module+0x162/0x190
> __do_sys_finit_module+0x162/0x190
> ? __ia32_sys_init_module+0x40/0x40
> ? __mutex_unlock_slowpath+0xb4/0x3f0
> ? wait_for_completion+0x240/0x240
> ? vfs_write+0x160/0x2a0
> ? lockdep_hardirqs_off+0xb5/0x100
> ? mark_held_locks+0x1a/0x90
> ? do_syscall_64+0x14/0x2a0
> do_syscall_64+0x72/0x2a0
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> Reported-by: Hulk Robot <[email protected]>
> Fixes: 702a4879ec33 ("spi: bitbang: Let spi_bitbang_start() take a reference to master")
> Signed-off-by: YueHaibing <[email protected]>
Reviewed-by: Mukesh Ojha <[email protected]>
Cheers,
-Mukesh
> ---
> drivers/spi/spi-bitbang.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
> index dd9a8c54..be95be4 100644
> --- a/drivers/spi/spi-bitbang.c
> +++ b/drivers/spi/spi-bitbang.c
> @@ -403,7 +403,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
> if (ret)
> spi_master_put(master);
>
> - return 0;
> + return ret;
> }
> EXPORT_SYMBOL_GPL(spi_bitbang_start);
>
On Thu, May 16, 2019 at 03:56:56PM +0800, YueHaibing wrote:
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
> Call Trace:
> dump_stack+0xa9/0x10e
> ? __list_del_entry_valid+0x45/0xd0
> ? __list_del_entry_valid+0x45/0xd0
> __kasan_report+0x171/0x18d
> ? __list_del_entry_valid+0x45/0xd0
> kasan_report+0xe/0x20
Please think hard before including complete backtraces in upstream
reports, they are very large and contain almost no useful information
relative to their size so often obscure the relevant content in your
message. If part of the backtrace is usefully illustrative then it's
usually better to pull out the relevant sections.
The patch
spi: bitbang: Fix NULL pointer dereference in spi_unregister_master
has been applied to the spi tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.2
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
From 5caaf29af5ca82d5da8bc1d0ad07d9e664ccf1d8 Mon Sep 17 00:00:00 2001
From: YueHaibing <[email protected]>
Date: Thu, 16 May 2019 15:56:56 +0800
Subject: [PATCH] spi: bitbang: Fix NULL pointer dereference in
spi_unregister_master
If spi_register_master fails in spi_bitbang_start
because device_add failure, We should return the
error code other than 0, otherwise calling
spi_bitbang_stop may trigger NULL pointer dereference
like this:
BUG: KASAN: null-ptr-deref in __list_del_entry_valid+0x45/0xd0
Read of size 8 at addr 0000000000000000 by task syz-executor.0/3661
CPU: 0 PID: 3661 Comm: syz-executor.0 Not tainted 5.1.0+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
dump_stack+0xa9/0x10e
? __list_del_entry_valid+0x45/0xd0
? __list_del_entry_valid+0x45/0xd0
__kasan_report+0x171/0x18d
? __list_del_entry_valid+0x45/0xd0
kasan_report+0xe/0x20
__list_del_entry_valid+0x45/0xd0
spi_unregister_controller+0x99/0x1b0
spi_lm70llp_attach+0x3ae/0x4b0 [spi_lm70llp]
? 0xffffffffc1128000
? klist_next+0x131/0x1e0
? driver_detach+0x40/0x40 [parport]
port_check+0x3b/0x50 [parport]
bus_for_each_dev+0x115/0x180
? subsys_dev_iter_exit+0x20/0x20
__parport_register_driver+0x1f0/0x210 [parport]
? 0xffffffffc1150000
do_one_initcall+0xb9/0x3b5
? perf_trace_initcall_level+0x270/0x270
? kasan_unpoison_shadow+0x30/0x40
? kasan_unpoison_shadow+0x30/0x40
do_init_module+0xe0/0x330
load_module+0x38eb/0x4270
? module_frob_arch_sections+0x20/0x20
? kernel_read_file+0x188/0x3f0
? find_held_lock+0x6d/0xd0
? fput_many+0x1a/0xe0
? __do_sys_finit_module+0x162/0x190
__do_sys_finit_module+0x162/0x190
? __ia32_sys_init_module+0x40/0x40
? __mutex_unlock_slowpath+0xb4/0x3f0
? wait_for_completion+0x240/0x240
? vfs_write+0x160/0x2a0
? lockdep_hardirqs_off+0xb5/0x100
? mark_held_locks+0x1a/0x90
? do_syscall_64+0x14/0x2a0
do_syscall_64+0x72/0x2a0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reported-by: Hulk Robot <[email protected]>
Fixes: 702a4879ec33 ("spi: bitbang: Let spi_bitbang_start() take a reference to master")
Signed-off-by: YueHaibing <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Axel Lin <[email protected]>
Reviewed-by: Mukesh Ojha <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
---
drivers/spi/spi-bitbang.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index 4243e53f9f7b..e8fd95276315 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -415,7 +415,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
if (ret)
spi_master_put(master);
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(spi_bitbang_start);
--
2.20.1
On 2019/5/16 17:51, Mark Brown wrote:
> On Thu, May 16, 2019 at 03:56:56PM +0800, YueHaibing wrote:
>
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
>> Call Trace:
>> dump_stack+0xa9/0x10e
>> ? __list_del_entry_valid+0x45/0xd0
>> ? __list_del_entry_valid+0x45/0xd0
>> __kasan_report+0x171/0x18d
>> ? __list_del_entry_valid+0x45/0xd0
>> kasan_report+0xe/0x20
>
> Please think hard before including complete backtraces in upstream
> reports, they are very large and contain almost no useful information
> relative to their size so often obscure the relevant content in your
> message. If part of the backtrace is usefully illustrative then it's
> usually better to pull out the relevant sections.
Thanks, got it.
>