63 lines
2.4 KiB
Diff
63 lines
2.4 KiB
Diff
From 9868ebc8e648e5791764a51567a23efae7170d9b Mon Sep 17 00:00:00 2001
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From: HATAYAMA Daisuke <d.hatayama@fujitsu.com>
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Date: Tue, 30 May 2023 19:38:35 +0900
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Subject: [PATCH 6/6] Fix segfault in arm64_is_kernel_exception_frame() when
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corrupt stack pointer address is given
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Due to the corrupted mapping fixed by the previous commit,
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arm64_is_kernel_exception_frame() can receive invalid stack pointer
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address via the 2nd argument; different NT_PRSTATUS contains different
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task's stack pointer address. However, macro STACK_OFFSET_TYPE() never
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checks if a given address is within the range of the kernel stack of
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the corresponding task and hence can result in referring to outside of
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bt->stackbuf.
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static int
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arm64_is_kernel_exception_frame(struct bt_info *bt, ulong stkptr)
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{
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struct arm64_pt_regs *regs;
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struct machine_specific *ms = machdep->machspec;
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regs = (struct arm64_pt_regs *)&bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(stkptr))];
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=> if (INSTACK(regs->sp, bt) && INSTACK(regs->regs[29], bt) &&
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!(regs->pstate & (0xffffffff00000000ULL | PSR_MODE32_BIT)) &&
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is_kernel_text(regs->pc) &&
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is_kernel_text(regs->regs[30] | ms->CONFIG_ARM64_KERNELPACMASK)) {
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To fix this issue, check if the given stack pointer address points to
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the range of the kernel stack of the corresponding task, and abort if
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it turns out to be invalid.
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Although the corrupted mapping has already been fixed, this fix is
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still needed because corrupt stack pointer address can still be passed
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here from different reasons. Consider, for example, that data on the
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kernel stack can be modified abnormally due to any kernel bugs or
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hardware issues.
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Signed-off-by: HATAYAMA Daisuke <d.hatayama@fujitsu.com>
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Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
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---
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defs.h | 5 ++++-
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1 file changed, 4 insertions(+), 1 deletion(-)
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diff --git a/defs.h b/defs.h
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index 6520d2f13f48..11fdc17e60d0 100644
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--- a/defs.h
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+++ b/defs.h
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@@ -976,7 +976,10 @@ struct bt_info {
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#define STACK_OFFSET_TYPE(OFF) \
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(((ulong)(OFF) > STACKSIZE()) ? \
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- (ulong)((ulong)(OFF) - (ulong)(bt->stackbase)) : (ulong)(OFF))
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+ (((ulong)(OFF) < (ulong)(bt->stackbase) || (ulong)(OFF) >= (ulong)(bt->stackbase) + STACKSIZE()) ? \
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+ error(FATAL, "invalid stack pointer is given\n") : \
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+ (ulong)((ulong)(OFF) - (ulong)(bt->stackbase))) : \
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+ (ulong)(OFF))
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#define GET_STACK_ULONG(OFF) \
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*((ulong *)((char *)(&bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(OFF))])))
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--
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2.37.1
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