There is a potential out-of-bounds access when using test_bit() on a
single word. The test_bit() and set_bit() functions operate on long
values, and when testing or setting a single word, they can exceed the
word boundary. KASAN detects this issue and produces a dump:
BUG: KASAN: slab-out-of-bounds in _scsih_add_device.constprop.0 (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 drivers/scsi/mpt3sas/mpt3sas_scsih.c:7331) mpt3sas
Write of size 8 at addr ffff8881d26e3c60 by task kworker/u1536:2/2965
For full log, please look at [1].
Make the allocation at least the size of sizeof(unsigned long) so that
set_bit() and test_bit() have sufficient room for read/write operations
without overwriting unallocated memory.
[1] Link: https://lore.kernel.org/all/[email protected]/
Fixes: c696f7b83ede ("scsi: mpt3sas: Implement device_remove_in_progress check in IOCTL path")
Cc: [email protected]
Suggested-by: Keith Busch <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
---
Changelog:
v2:
* Do the same protection in krealloc() in
_base_check_ioc_facts_changes, as suggested by Keith.
---
drivers/scsi/mpt3sas/mpt3sas_base.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 258647fc6bdd..cc17204721c2 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -8512,6 +8512,12 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
ioc->pd_handles_sz = (ioc->facts.MaxDevHandle / 8);
if (ioc->facts.MaxDevHandle % 8)
ioc->pd_handles_sz++;
+ /* pd_handles_sz should have, at least, the minimal room
+ * for set_bit()/test_bit(), otherwise out-of-memory touch
+ * may occur
+ */
+ ioc->pd_handles_sz = ALIGN(ioc->pd_handles_sz, sizeof(unsigned long));
+
ioc->pd_handles = kzalloc(ioc->pd_handles_sz,
GFP_KERNEL);
if (!ioc->pd_handles) {
@@ -8529,6 +8535,12 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
ioc->pend_os_device_add_sz = (ioc->facts.MaxDevHandle / 8);
if (ioc->facts.MaxDevHandle % 8)
ioc->pend_os_device_add_sz++;
+
+ /* pend_os_device_add_sz should have, at least, the minimal room
+ * for set_bit()/test_bit(), otherwise out-of-memory may occur
+ */
+ ioc->pend_os_device_add_sz = ALIGN(ioc->pend_os_device_add_sz,
+ sizeof(unsigned long));
ioc->pend_os_device_add = kzalloc(ioc->pend_os_device_add_sz,
GFP_KERNEL);
if (!ioc->pend_os_device_add) {
@@ -8820,6 +8832,11 @@ _base_check_ioc_facts_changes(struct MPT3SAS_ADAPTER *ioc)
if (ioc->facts.MaxDevHandle % 8)
pd_handles_sz++;
+ /* pd_handles should have, at least, the minimal room
+ * for set_bit()/test_bit(), otherwise out-of-memory touch
+ * may occur
+ */
+ pd_handles_sz = ALIGN(pd_handles_sz, sizeof(unsigned long));
pd_handles = krealloc(ioc->pd_handles, pd_handles_sz,
GFP_KERNEL);
if (!pd_handles) {
--
2.43.0
On Wed, Jun 05, 2024 at 01:55:29AM -0700, Breno Leitao wrote:
> There is a potential out-of-bounds access when using test_bit() on a
> single word. The test_bit() and set_bit() functions operate on long
> values, and when testing or setting a single word, they can exceed the
> word boundary. KASAN detects this issue and produces a dump:
>
> BUG: KASAN: slab-out-of-bounds in _scsih_add_device.constprop.0 (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 drivers/scsi/mpt3sas/mpt3sas_scsih.c:7331) mpt3sas
>
> Write of size 8 at addr ffff8881d26e3c60 by task kworker/u1536:2/2965
>
> For full log, please look at [1].
>
> Make the allocation at least the size of sizeof(unsigned long) so that
> set_bit() and test_bit() have sufficient room for read/write operations
> without overwriting unallocated memory.
Looks good.
Reviewed-by: Keith Busch <[email protected]>
On Wed, 05 Jun 2024 01:55:29 -0700, Breno Leitao wrote:
> There is a potential out-of-bounds access when using test_bit() on a
> single word. The test_bit() and set_bit() functions operate on long
> values, and when testing or setting a single word, they can exceed the
> word boundary. KASAN detects this issue and produces a dump:
>
> BUG: KASAN: slab-out-of-bounds in _scsih_add_device.constprop.0 (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 drivers/scsi/mpt3sas/mpt3sas_scsih.c:7331) mpt3sas
>
> [...]
Applied to 6.10/scsi-fixes, thanks!
[1/1] mpt3sas: Avoid test/set_bit() operating in non-allocated memory
https://git.kernel.org/mkp/scsi/c/4254dfeda82f
--
Martin K. Petersen Oracle Linux Engineering
From: Breno Leitao <[email protected]>
> Sent: 05 June 2024 09:55
>
> There is a potential out-of-bounds access when using test_bit() on a
> single word. The test_bit() and set_bit() functions operate on long
> values, and when testing or setting a single word, they can exceed the
> word boundary. KASAN detects this issue and produces a dump:
>
> BUG: KASAN: slab-out-of-bounds in _scsih_add_device.constprop.0
> (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29
> drivers/scsi/mpt3sas/mpt3sas_scsih.c:7331) mpt3sas
>
> Write of size 8 at addr ffff8881d26e3c60 by task kworker/u1536:2/2965
>
> For full log, please look at [1].
>
> Make the allocation at least the size of sizeof(unsigned long) so that
> set_bit() and test_bit() have sufficient room for read/write operations
> without overwriting unallocated memory.
>
...
> @@ -8512,6 +8512,12 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
> ioc->pd_handles_sz = (ioc->facts.MaxDevHandle / 8);
> if (ioc->facts.MaxDevHandle % 8)
> ioc->pd_handles_sz++;
> + /* pd_handles_sz should have, at least, the minimal room
> + * for set_bit()/test_bit(), otherwise out-of-memory touch
> + * may occur
> + */
> + ioc->pd_handles_sz = ALIGN(ioc->pd_handles_sz, sizeof(unsigned long));
> +
> ioc->pd_handles = kzalloc(ioc->pd_handles_sz,
> GFP_KERNEL);
That is entirely stupid code.
IIRC there is a BITMAP_SIZE() that does ((x) + 63u) & ~63)/8
(on 64bit systems).
David
-
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