Commit-ID: fa33215422fd415a07ec2a00e9f1acdaf0fa8e94 Gitweb: https://git.kernel.org/tip/fa33215422fd415a07ec2a00e9f1acdaf0fa8e94 Author: Andy Lutomirski <luto@xxxxxxxxxx> AuthorDate: Sun, 14 Apr 2019 17:59:39 +0200 Committer: Borislav Petkov <bp@xxxxxxx> CommitDate: Wed, 17 Apr 2019 12:26:50 +0200 x86/dumpstack: Fix off-by-one errors in stack identification The get_stack_info() function is off-by-one when checking whether an address is on a IRQ stack or a IST stack. This prevents an overflowed IRQ or IST stack from being dumped properly. [ tglx: Do the same for 32-bit ] Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: x86-ml <x86@xxxxxxxxxx> Link: https://lkml.kernel.org/r/20190414160143.785651055@xxxxxxxxxxxxx --- arch/x86/kernel/dumpstack_32.c | 4 ++-- arch/x86/kernel/dumpstack_64.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index cd53f3030e40..d305440ebe9c 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -41,7 +41,7 @@ static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info) * This is a software stack, so 'end' can be a valid stack pointer. * It just means the stack is empty. */ - if (stack <= begin || stack > end) + if (stack < begin || stack > end) return false; info->type = STACK_TYPE_IRQ; @@ -66,7 +66,7 @@ static bool in_softirq_stack(unsigned long *stack, struct stack_info *info) * This is a software stack, so 'end' can be a valid stack pointer. * It just means the stack is empty. */ - if (stack <= begin || stack > end) + if (stack < begin || stack > end) return false; info->type = STACK_TYPE_SOFTIRQ; diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 5cdb9e84da57..90f0fa88cbb3 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -65,7 +65,7 @@ static bool in_exception_stack(unsigned long *stack, struct stack_info *info) begin = end - (exception_stack_sizes[k] / sizeof(long)); regs = (struct pt_regs *)end - 1; - if (stack <= begin || stack >= end) + if (stack < begin || stack >= end) continue; info->type = STACK_TYPE_EXCEPTION + k; @@ -88,7 +88,7 @@ static bool in_irq_stack(unsigned long *stack, struct stack_info *info) * This is a software stack, so 'end' can be a valid stack pointer. * It just means the stack is empty. */ - if (stack <= begin || stack > end) + if (stack < begin || stack >= end) return false; info->type = STACK_TYPE_IRQ;
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