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Groups > linux.kernel > #1237419 > unrolled thread
| Started by | Stephen Smalley <sds@tycho.nsa.gov> |
|---|---|
| First post | 2015-10-01 15:10 +0200 |
| Last post | 2015-10-02 09:50 +0200 |
| Articles | 3 — 3 participants |
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[PATCH] x86/mm: Set NX on gap between __ex_table and rodata Stephen Smalley <sds@tycho.nsa.gov> - 2015-10-01 15:10 +0200
Re: [PATCH] x86/mm: Set NX on gap between __ex_table and rodata Kees Cook <keescook@chromium.org> - 2015-10-01 18:40 +0200
[tip:x86/urgent] x86/mm: Set NX on gap between __ex_table and rodata tip-bot for Stephen Smalley <tipbot@zytor.com> - 2015-10-02 09:50 +0200
| From | Stephen Smalley <sds@tycho.nsa.gov> |
|---|---|
| Date | 2015-10-01 15:10 +0200 |
| Subject | [PATCH] x86/mm: Set NX on gap between __ex_table and rodata |
| Message-ID | <qeLMv-53B-39@gated-at.bofh.it> |
Unused space between the end of __ex_table and the start of rodata can be left W+x in the kernel page tables. Extend the setting of the NX bit to cover this gap by starting from text_end rather than rodata_start. Before: ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte 0xffffffff81754000-0xffffffff81800000 688K RW GLB x pte 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd 0xffffffff82200000-0xffffffffa0000000 478M pmd After: ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte 0xffffffff81754000-0xffffffff81800000 688K RW GLB NX pte 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd 0xffffffff82200000-0xffffffffa0000000 478M pmd Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> --- arch/x86/mm/init_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 30564e2..df48430 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1132,7 +1132,7 @@ void mark_rodata_ro(void) * has been zapped already via cleanup_highmem(). */ all_end = roundup((unsigned long)_brk_end, PMD_SIZE); - set_memory_nx(rodata_start, (all_end - rodata_start) >> PAGE_SHIFT); + set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT); rodata_test(); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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| From | Kees Cook <keescook@chromium.org> |
|---|---|
| Date | 2015-10-01 18:40 +0200 |
| Message-ID | <qeP3I-1CP-29@gated-at.bofh.it> |
| In reply to | #1237419 |
On Thu, Oct 1, 2015 at 6:04 AM, Stephen Smalley <sds@tycho.nsa.gov> wrote: > Unused space between the end of __ex_table and the start of rodata > can be left W+x in the kernel page tables. Extend the setting > of the NX bit to cover this gap by starting from text_end rather than > rodata_start. > > Before: > ---[ High Kernel Mapping ]--- > 0xffffffff80000000-0xffffffff81000000 16M pmd > 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd > 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte > 0xffffffff81754000-0xffffffff81800000 688K RW GLB x pte > 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd > 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte > 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte > 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd > 0xffffffff82200000-0xffffffffa0000000 478M pmd > > After: > ---[ High Kernel Mapping ]--- > 0xffffffff80000000-0xffffffff81000000 16M pmd > 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd > 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte > 0xffffffff81754000-0xffffffff81800000 688K RW GLB NX pte > 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd > 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte > 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte > 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd > 0xffffffff82200000-0xffffffffa0000000 478M pmd > > Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Kees Cook <keescook@chromium.org> -Kees > --- > arch/x86/mm/init_64.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 30564e2..df48430 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1132,7 +1132,7 @@ void mark_rodata_ro(void) > * has been zapped already via cleanup_highmem(). > */ > all_end = roundup((unsigned long)_brk_end, PMD_SIZE); > - set_memory_nx(rodata_start, (all_end - rodata_start) >> PAGE_SHIFT); > + set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT); > > rodata_test(); > > -- > 2.1.0 > -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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| From | tip-bot for Stephen Smalley <tipbot@zytor.com> |
|---|---|
| Date | 2015-10-02 09:50 +0200 |
| Subject | [tip:x86/urgent] x86/mm: Set NX on gap between __ex_table and rodata |
| Message-ID | <qf3gm-5mM-29@gated-at.bofh.it> |
| In reply to | #1237419 |
Commit-ID: ab76f7b4ab2397ffdd2f1eb07c55697d19991d10 Gitweb: http://git.kernel.org/tip/ab76f7b4ab2397ffdd2f1eb07c55697d19991d10 Author: Stephen Smalley <sds@tycho.nsa.gov> AuthorDate: Thu, 1 Oct 2015 09:04:22 -0400 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Fri, 2 Oct 2015 09:21:06 +0200 x86/mm: Set NX on gap between __ex_table and rodata Unused space between the end of __ex_table and the start of rodata can be left W+x in the kernel page tables. Extend the setting of the NX bit to cover this gap by starting from text_end rather than rodata_start. Before: ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte 0xffffffff81754000-0xffffffff81800000 688K RW GLB x pte 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd 0xffffffff82200000-0xffffffffa0000000 478M pmd After: ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte 0xffffffff81754000-0xffffffff81800000 688K RW GLB NX pte 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd 0xffffffff82200000-0xffffffffa0000000 478M pmd Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.gov Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/mm/init_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 30564e2..df48430 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1132,7 +1132,7 @@ void mark_rodata_ro(void) * has been zapped already via cleanup_highmem(). */ all_end = roundup((unsigned long)_brk_end, PMD_SIZE); - set_memory_nx(rodata_start, (all_end - rodata_start) >> PAGE_SHIFT); + set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT); rodata_test(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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