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* [PATCH -fixes v2] riscv: Fix out-of-bounds when accessing Andes per hart vendor extension array
@ 2024-08-14 19:26 Alexandre Ghiti
  2024-08-14 20:21 ` Charlie Jenkins
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Alexandre Ghiti @ 2024-08-14 19:26 UTC (permalink / raw)
  To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Charlie Jenkins,
	Andy Chiu, Alexandre Ghiti, linux-riscv, linux-kernel

The out-of-bounds access is reported by UBSAN:

[    0.000000] UBSAN: array-index-out-of-bounds in ../arch/riscv/kernel/vendor_extensions.c:41:66
[    0.000000] index -1 is out of range for type 'riscv_isavendorinfo [32]'
[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.11.0-rc2ubuntu-defconfig #2
[    0.000000] Hardware name: riscv-virtio,qemu (DT)
[    0.000000] Call Trace:
[    0.000000] [<ffffffff94e078ba>] dump_backtrace+0x32/0x40
[    0.000000] [<ffffffff95c83c1a>] show_stack+0x38/0x44
[    0.000000] [<ffffffff95c94614>] dump_stack_lvl+0x70/0x9c
[    0.000000] [<ffffffff95c94658>] dump_stack+0x18/0x20
[    0.000000] [<ffffffff95c8bbb2>] ubsan_epilogue+0x10/0x46
[    0.000000] [<ffffffff95485a82>] __ubsan_handle_out_of_bounds+0x94/0x9c
[    0.000000] [<ffffffff94e09442>] __riscv_isa_vendor_extension_available+0x90/0x92
[    0.000000] [<ffffffff94e043b6>] riscv_cpufeature_patch_func+0xc4/0x148
[    0.000000] [<ffffffff94e035f8>] _apply_alternatives+0x42/0x50
[    0.000000] [<ffffffff95e04196>] apply_boot_alternatives+0x3c/0x100
[    0.000000] [<ffffffff95e05b52>] setup_arch+0x85a/0x8bc
[    0.000000] [<ffffffff95e00ca0>] start_kernel+0xa4/0xfb6

The dereferencing using cpu should actually not happen, so remove it.

Fixes: 23c996fc2bc1 ("riscv: Extend cpufeature.c to detect vendor extensions")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 arch/riscv/kernel/vendor_extensions.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/vendor_extensions.c b/arch/riscv/kernel/vendor_extensions.c
index b6c1e7b5d34b..a8126d118341 100644
--- a/arch/riscv/kernel/vendor_extensions.c
+++ b/arch/riscv/kernel/vendor_extensions.c
@@ -38,7 +38,7 @@ bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsig
 	#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_ANDES
 	case ANDES_VENDOR_ID:
 		bmap = &riscv_isa_vendor_ext_list_andes.all_harts_isa_bitmap;
-		cpu_bmap = &riscv_isa_vendor_ext_list_andes.per_hart_isa_bitmap[cpu];
+		cpu_bmap = riscv_isa_vendor_ext_list_andes.per_hart_isa_bitmap;
 		break;
 	#endif
 	default:
-- 
2.39.2


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end of thread, other threads:[~2024-08-15 17:50 UTC | newest]

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2024-08-14 19:26 [PATCH -fixes v2] riscv: Fix out-of-bounds when accessing Andes per hart vendor extension array Alexandre Ghiti
2024-08-14 20:21 ` Charlie Jenkins
2024-08-14 22:26 ` Conor Dooley
2024-08-15  5:23   ` Alexandre Ghiti
2024-08-15 17:50 ` patchwork-bot+linux-riscv

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