[PATCH v1] regmap-irq: Fix out-of-bounds access when allocating config buffers

[PATCH v1] regmap-irq: Fix out-of-bounds access when allocating config buffers

[Isaac J. Manjarres]

When allocating the 2D array for handling IRQ type registers in
regmap_add_irq_chip_fwnode(), the intent is to allocate a matrix
with num_config_bases rows and num_config_regs columns.

This is currently handled by allocating a buffer to hold a pointer for
each row (i.e. num_config_bases). After that, the logic attempts to
allocate the memory required to hold the register configuration for
each row. However, instead of doing this allocation for each row
(i.e. num_config_bases allocations), the logic erroneously does this
allocation num_config_regs number of times.

This scenario can lead to out-of-bounds accesses when num_config_regs
is greater than num_config_bases. Fix this by updating the terminating
condition of the loop that allocates the memory for holding the register
configuration to allocate memory only for each row in the matrix.

Amit Pundir reported a crash that was occurring on his db845c device
due to memory corruption (see "Closes" tag for Amit's report). The KASAN
report below helped narrow it down to this issue:

[   14.033877][    T1] ==================================================================
[   14.042507][    T1] BUG: KASAN: invalid-access in regmap_add_irq_chip_fwnode+0x594/0x1364
[   14.050796][    T1] Write of size 8 at addr 06ffff8081021850 by task init/1
[   14.057841][    T1] Pointer tag: [06], memory tag: [fe]
[   14.063124][    T1]
[   14.065349][    T1] CPU: 2 PID: 1 Comm: init Tainted: G        W   E      6.4.0-mainline-g6a4b67fef3e2 #1
[   14.075014][    T1] Hardware name: Thundercomm Dragonboard 845c (DT)
[   14.081432][    T1] Call trace:
[   14.084618][    T1]  dump_backtrace+0xe8/0x108
[   14.089144][    T1]  show_stack+0x18/0x30
[   14.093215][    T1]  dump_stack_lvl+0x50/0x6c
[   14.097642][    T1]  print_report+0x178/0x4c0
[   14.102070][    T1]  kasan_report+0xd4/0x12c
[   14.106407][    T1]  kasan_tag_mismatch+0x28/0x40
[   14.111178][    T1]  __hwasan_tag_mismatch+0x2c/0x5c
[   14.116222][    T1]  regmap_add_irq_chip_fwnode+0x594/0x1364
[   14.121961][    T1]  devm_regmap_add_irq_chip+0xb8/0x144
[   14.127346][    T1]  wcd934x_slim_status+0x210/0x28c [wcd934x]
[   14.133307][    T1]  slim_device_alloc_laddr+0x1ac/0x1ec [slimbus]
[   14.139669][    T1]  slim_device_probe+0x80/0x124 [slimbus]
[   14.145394][    T1]  really_probe+0x250/0x4d8
[   14.149826][    T1]  __driver_probe_device+0x104/0x1ac
[   14.155041][    T1]  driver_probe_device+0x80/0x218
[   14.159990][    T1]  __driver_attach+0x19c/0x2e4
[   14.164678][    T1]  bus_for_each_dev+0x158/0x1b4
[   14.169454][    T1]  driver_attach+0x34/0x44
[   14.173790][    T1]  bus_add_driver+0x1fc/0x328
[   14.178390][    T1]  driver_register+0xdc/0x1b4
[   14.182995][    T1]  __slim_driver_register+0x6c/0x84 [slimbus]
[   14.189068][    T1]  init_module+0x20/0xfe4 [wcd934x]
[   14.194219][    T1]  do_one_initcall+0x110/0x418
[   14.198916][    T1]  do_init_module+0x124/0x30c
[   14.203521][    T1]  load_module+0x1938/0x1ab0
[   14.208034][    T1]  __arm64_sys_finit_module+0x110/0x138
[   14.213509][    T1]  invoke_syscall+0x70/0x170
[   14.218015][    T1]  el0_svc_common+0xf0/0x138
[   14.222523][    T1]  do_el0_svc+0x40/0xb8
[   14.226596][    T1]  el0_svc+0x2c/0x78
[   14.230405][    T1]  el0t_64_sync_handler+0x68/0xb4
[   14.235354][    T1]  el0t_64_sync+0x19c/0x1a0
[   14.239778][    T1]
[   14.242004][    T1] The buggy address belongs to the object at ffffff8081021850
[   14.242004][    T1]  which belongs to the cache kmalloc-8 of size 8
[   14.255669][    T1] The buggy address is located 0 bytes inside of
[   14.255669][    T1]  8-byte region [ffffff8081021850, ffffff8081021858)
[   14.255685][    T1]
[   14.255689][    T1] The buggy address belongs to the physical page:
[   14.255699][    T1] page:0000000080887a30 refcount:1 mapcount:0 mapping:0000000000000000 index:0x85ffff8081021ee0 pfn:0x101021
[   14.275062][    T1] flags: 0x4000000000000200(slab|zone=1|kasantag=0x0)
[   14.275078][    T1] page_type: 0xffffffff()
[   14.275091][    T1] raw: 4000000000000200 49ffff8080002200 dead000000000122 0000000000000000
[   14.275103][    T1] raw: 85ffff8081021ee0 00000000810000ea 00000001ffffffff 0000000000000000
[   14.275110][    T1] page dumped because: kasan: bad access detected
[   14.275116][    T1]
[   14.275119][    T1] Memory state around the buggy address:
[   14.275125][    T1]  ffffff8081021600: fe fe fe 9a fe fe 5b 3c fe fe c9 fe b4 3f fe 54
[   14.275133][    T1]  ffffff8081021700: fe fe ad 6b fe fe fe 87 fe fe 39 c9 fe 03 fe ea
[   14.275143][    T1] >ffffff8081021800: fe fe e1 fe 06 fe fe 21 fe fe e7 fe de fe fe 70
[   14.275149][    T1]                                   ^
[   14.371674][    T1]  ffffff8081021900: d7 fe fe 87 fe a0 fe fe fe 80 e0 f0 05 fe fe fe
[   14.379667][    T1]  ffffff8081021a00: 94 fe 31 fe fe e5 c8 00 d0 fe a1 fe fe e2 e5 fe
[   14.387664][    T1] ==================================================================

Fixes: faa87ce9196d ("regmap-irq: Introduce config registers for irq types")
Reported-by: Amit Pundir <amit.pundir@linaro.org>
Closes: https://lore.kernel.org/all/CAMi1Hd04mu6JojT3y6wyN2YeVkPR5R3qnkKJ8iR8if_YByCn4w@mail.gmail.com/
Tested-by: John Stultz <jstultz@google.com>
Cc: stable@vger.kernel.org # v6.0+
Cc: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
---
 drivers/base/regmap/regmap-irq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index ced0dcf86e0b..45fd13ef13fc 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -717,7 +717,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 		if (!d->config_buf)
 			goto err_alloc;
 
-		for (i = 0; i < chip->num_config_regs; i++) {
+		for (i = 0; i < chip->num_config_bases; i++) {
 			d->config_buf[i] = kcalloc(chip->num_config_regs,
 						   sizeof(**d->config_buf),
 						   GFP_KERNEL);
-- 
2.41.0.255.g8b1d071c50-goog

Re: [PATCH v1] regmap-irq: Fix out-of-bounds access when allocating config buffers

[Mark Brown]

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On Tue, Jul 11, 2023 at 12:30:58PM -0700, Isaac J. Manjarres wrote:

> [   14.033877][    T1] ==================================================================
> [   14.042507][    T1] BUG: KASAN: invalid-access in regmap_add_irq_chip_fwnode+0x594/0x1364
> [   14.050796][    T1] Write of size 8 at addr 06ffff8081021850 by task init/1
> [   14.057841][    T1] Pointer tag: [06], memory tag: [fe]
> [   14.063124][    T1]
> [   14.065349][    T1] CPU: 2 PID: 1 Comm: init Tainted: G        W   E      6.4.0-mainline-g6a4b67fef3e2 #1
> [   14.075014][    T1] Hardware name: Thundercomm Dragonboard 845c (DT)
> [   14.081432][    T1] Call trace:

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 (it often is
for search engines if nothing else) then it's usually better to pull out
the relevant sections.

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Re: [PATCH v1] regmap-irq: Fix out-of-bounds access when allocating config buffers

[Isaac Manjarres]

On Tue, Jul 11, 2023 at 08:50:08PM +0100, Mark Brown wrote:
> On Tue, Jul 11, 2023 at 12:30:58PM -0700, Isaac J. Manjarres wrote:
> 
> > [   14.033877][    T1] ==================================================================
> > [   14.042507][    T1] BUG: KASAN: invalid-access in regmap_add_irq_chip_fwnode+0x594/0x1364
> > [   14.050796][    T1] Write of size 8 at addr 06ffff8081021850 by task init/1
> > [   14.057841][    T1] Pointer tag: [06], memory tag: [fe]
> > [   14.063124][    T1]
> > [   14.065349][    T1] CPU: 2 PID: 1 Comm: init Tainted: G        W   E      6.4.0-mainline-g6a4b67fef3e2 #1
> > [   14.075014][    T1] Hardware name: Thundercomm Dragonboard 845c (DT)
> > [   14.081432][    T1] Call trace:
> 
> 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 (it often is
> for search engines if nothing else) then it's usually better to pull out
> the relevant sections.

Hi Mark,

Thanks for your feedback. I'll go ahead and send out a new version of
the patch with a trimmed down commit message.

Thanks,
Isaac

Re: [PATCH v1] regmap-irq: Fix out-of-bounds access when allocating config buffers

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 688 bytes --]

On Tue, Jul 11, 2023 at 03:11:22PM -0700, Isaac Manjarres wrote:
> On Tue, Jul 11, 2023 at 08:50:08PM +0100, Mark Brown wrote:

> > 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 (it often is
> > for search engines if nothing else) then it's usually better to pull out
> > the relevant sections.

> Thanks for your feedback. I'll go ahead and send out a new version of
> the patch with a trimmed down commit message.

It's OK, I did some local edits myself.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH v1] regmap-irq: Fix out-of-bounds access when allocating config buffers

[Isaac Manjarres]

On Tue, Jul 11, 2023 at 11:24:59PM +0100, Mark Brown wrote:
> On Tue, Jul 11, 2023 at 03:11:22PM -0700, Isaac Manjarres wrote:
> > On Tue, Jul 11, 2023 at 08:50:08PM +0100, Mark Brown wrote:
> 
> > > 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 (it often is
> > > for search engines if nothing else) then it's usually better to pull out
> > > the relevant sections.
> 
> > Thanks for your feedback. I'll go ahead and send out a new version of
> > the patch with a trimmed down commit message.
> 
> It's OK, I did some local edits myself.

Thanks Mark!

--Isaac

Re: [PATCH v1] regmap-irq: Fix out-of-bounds access when allocating config buffers

[Amit Pundir]

On Wed, 12 Jul 2023 at 01:01, Isaac J. Manjarres
<isaacmanjarres@google.com> wrote:
>
> When allocating the 2D array for handling IRQ type registers in
> regmap_add_irq_chip_fwnode(), the intent is to allocate a matrix
> with num_config_bases rows and num_config_regs columns.
>
> This is currently handled by allocating a buffer to hold a pointer for
> each row (i.e. num_config_bases). After that, the logic attempts to
> allocate the memory required to hold the register configuration for
> each row. However, instead of doing this allocation for each row
> (i.e. num_config_bases allocations), the logic erroneously does this
> allocation num_config_regs number of times.
>
> This scenario can lead to out-of-bounds accesses when num_config_regs
> is greater than num_config_bases. Fix this by updating the terminating
> condition of the loop that allocates the memory for holding the register
> configuration to allocate memory only for each row in the matrix.
>
> Amit Pundir reported a crash that was occurring on his db845c device
> due to memory corruption (see "Closes" tag for Amit's report). The KASAN
> report below helped narrow it down to this issue:

Tested-by: Amit Pundir <amit.pundir@linaro.org> # tested on Dragonboard 845c

>
> [   14.033877][    T1] ==================================================================
> [   14.042507][    T1] BUG: KASAN: invalid-access in regmap_add_irq_chip_fwnode+0x594/0x1364
> [   14.050796][    T1] Write of size 8 at addr 06ffff8081021850 by task init/1
> [   14.057841][    T1] Pointer tag: [06], memory tag: [fe]
> [   14.063124][    T1]
> [   14.065349][    T1] CPU: 2 PID: 1 Comm: init Tainted: G        W   E      6.4.0-mainline-g6a4b67fef3e2 #1
> [   14.075014][    T1] Hardware name: Thundercomm Dragonboard 845c (DT)
> [   14.081432][    T1] Call trace:
> [   14.084618][    T1]  dump_backtrace+0xe8/0x108
> [   14.089144][    T1]  show_stack+0x18/0x30
> [   14.093215][    T1]  dump_stack_lvl+0x50/0x6c
> [   14.097642][    T1]  print_report+0x178/0x4c0
> [   14.102070][    T1]  kasan_report+0xd4/0x12c
> [   14.106407][    T1]  kasan_tag_mismatch+0x28/0x40
> [   14.111178][    T1]  __hwasan_tag_mismatch+0x2c/0x5c
> [   14.116222][    T1]  regmap_add_irq_chip_fwnode+0x594/0x1364
> [   14.121961][    T1]  devm_regmap_add_irq_chip+0xb8/0x144
> [   14.127346][    T1]  wcd934x_slim_status+0x210/0x28c [wcd934x]
> [   14.133307][    T1]  slim_device_alloc_laddr+0x1ac/0x1ec [slimbus]
> [   14.139669][    T1]  slim_device_probe+0x80/0x124 [slimbus]
> [   14.145394][    T1]  really_probe+0x250/0x4d8
> [   14.149826][    T1]  __driver_probe_device+0x104/0x1ac
> [   14.155041][    T1]  driver_probe_device+0x80/0x218
> [   14.159990][    T1]  __driver_attach+0x19c/0x2e4
> [   14.164678][    T1]  bus_for_each_dev+0x158/0x1b4
> [   14.169454][    T1]  driver_attach+0x34/0x44
> [   14.173790][    T1]  bus_add_driver+0x1fc/0x328
> [   14.178390][    T1]  driver_register+0xdc/0x1b4
> [   14.182995][    T1]  __slim_driver_register+0x6c/0x84 [slimbus]
> [   14.189068][    T1]  init_module+0x20/0xfe4 [wcd934x]
> [   14.194219][    T1]  do_one_initcall+0x110/0x418
> [   14.198916][    T1]  do_init_module+0x124/0x30c
> [   14.203521][    T1]  load_module+0x1938/0x1ab0
> [   14.208034][    T1]  __arm64_sys_finit_module+0x110/0x138
> [   14.213509][    T1]  invoke_syscall+0x70/0x170
> [   14.218015][    T1]  el0_svc_common+0xf0/0x138
> [   14.222523][    T1]  do_el0_svc+0x40/0xb8
> [   14.226596][    T1]  el0_svc+0x2c/0x78
> [   14.230405][    T1]  el0t_64_sync_handler+0x68/0xb4
> [   14.235354][    T1]  el0t_64_sync+0x19c/0x1a0
> [   14.239778][    T1]
> [   14.242004][    T1] The buggy address belongs to the object at ffffff8081021850
> [   14.242004][    T1]  which belongs to the cache kmalloc-8 of size 8
> [   14.255669][    T1] The buggy address is located 0 bytes inside of
> [   14.255669][    T1]  8-byte region [ffffff8081021850, ffffff8081021858)
> [   14.255685][    T1]
> [   14.255689][    T1] The buggy address belongs to the physical page:
> [   14.255699][    T1] page:0000000080887a30 refcount:1 mapcount:0 mapping:0000000000000000 index:0x85ffff8081021ee0 pfn:0x101021
> [   14.275062][    T1] flags: 0x4000000000000200(slab|zone=1|kasantag=0x0)
> [   14.275078][    T1] page_type: 0xffffffff()
> [   14.275091][    T1] raw: 4000000000000200 49ffff8080002200 dead000000000122 0000000000000000
> [   14.275103][    T1] raw: 85ffff8081021ee0 00000000810000ea 00000001ffffffff 0000000000000000
> [   14.275110][    T1] page dumped because: kasan: bad access detected
> [   14.275116][    T1]
> [   14.275119][    T1] Memory state around the buggy address:
> [   14.275125][    T1]  ffffff8081021600: fe fe fe 9a fe fe 5b 3c fe fe c9 fe b4 3f fe 54
> [   14.275133][    T1]  ffffff8081021700: fe fe ad 6b fe fe fe 87 fe fe 39 c9 fe 03 fe ea
> [   14.275143][    T1] >ffffff8081021800: fe fe e1 fe 06 fe fe 21 fe fe e7 fe de fe fe 70
> [   14.275149][    T1]                                   ^
> [   14.371674][    T1]  ffffff8081021900: d7 fe fe 87 fe a0 fe fe fe 80 e0 f0 05 fe fe fe
> [   14.379667][    T1]  ffffff8081021a00: 94 fe 31 fe fe e5 c8 00 d0 fe a1 fe fe e2 e5 fe
> [   14.387664][    T1] ==================================================================
>
> Fixes: faa87ce9196d ("regmap-irq: Introduce config registers for irq types")
> Reported-by: Amit Pundir <amit.pundir@linaro.org>
> Closes: https://lore.kernel.org/all/CAMi1Hd04mu6JojT3y6wyN2YeVkPR5R3qnkKJ8iR8if_YByCn4w@mail.gmail.com/
> Tested-by: John Stultz <jstultz@google.com>
> Cc: stable@vger.kernel.org # v6.0+
> Cc: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
> Cc: Saravana Kannan <saravanak@google.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
> ---
>  drivers/base/regmap/regmap-irq.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
> index ced0dcf86e0b..45fd13ef13fc 100644
> --- a/drivers/base/regmap/regmap-irq.c
> +++ b/drivers/base/regmap/regmap-irq.c
> @@ -717,7 +717,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
>                 if (!d->config_buf)
>                         goto err_alloc;
>
> -               for (i = 0; i < chip->num_config_regs; i++) {
> +               for (i = 0; i < chip->num_config_bases; i++) {
>                         d->config_buf[i] = kcalloc(chip->num_config_regs,
>                                                    sizeof(**d->config_buf),
>                                                    GFP_KERNEL);
> --
> 2.41.0.255.g8b1d071c50-goog
>

Re: [PATCH v1] regmap-irq: Fix out-of-bounds access when allocating config buffers

[Mark Brown]

On Tue, 11 Jul 2023 12:30:58 -0700, Isaac J. Manjarres wrote:
> When allocating the 2D array for handling IRQ type registers in
> regmap_add_irq_chip_fwnode(), the intent is to allocate a matrix
> with num_config_bases rows and num_config_regs columns.
> 
> This is currently handled by allocating a buffer to hold a pointer for
> each row (i.e. num_config_bases). After that, the logic attempts to
> allocate the memory required to hold the register configuration for
> each row. However, instead of doing this allocation for each row
> (i.e. num_config_bases allocations), the logic erroneously does this
> allocation num_config_regs number of times.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

Thanks!

[1/1] regmap-irq: Fix out-of-bounds access when allocating config buffers
      commit: 963b54df82b6d6206d7def273390bf3f7af558e1

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