From: Breno Leitao leitao@debian.org
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/u1536:2/2965For 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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