rseq: Fix: Increase AT_VECTOR_SIZE_BASE to match rseq auxvec entries

[RFC PATCH tip] rseq: Fix: Increase AT_VECTOR_SIZE_BASE to match rseq auxvec entries

Posted by Mathieu Desnoyers 2 years, 8 months ago

Two new auxiliary vector entries are introduced for rseq without
matching increment of the AT_VECTOR_SIZE_BASE, which causes failures
with CONFIG_HARDENED_USERCOPY=y.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/Y7XJKZhuU9VJZQ11@dev-arch.thelio-3990X
Fixes: 317c8194e6ae ("rseq: Introduce feature size and alignment ELF auxiliary vector entries")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 include/linux/auxvec.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/auxvec.h b/include/linux/auxvec.h
index f68d0ec2d740..407f7005e6d6 100644
--- a/include/linux/auxvec.h
+++ b/include/linux/auxvec.h
@@ -4,6 +4,6 @@
 
 #include <uapi/linux/auxvec.h>
 
-#define AT_VECTOR_SIZE_BASE 20 /* NEW_AUX_ENT entries in auxiliary table */
+#define AT_VECTOR_SIZE_BASE 22 /* NEW_AUX_ENT entries in auxiliary table */
   /* number of "#define AT_.*" above, minus {AT_NULL, AT_IGNORE, AT_NOTELF} */
 #endif /* _LINUX_AUXVEC_H */
-- 
2.25.1

Re: [RFC PATCH tip] rseq: Fix: Increase AT_VECTOR_SIZE_BASE to match rseq auxvec entries

Posted by Nathan Chancellor 2 years, 8 months ago

On Wed, Jan 04, 2023 at 02:20:54PM -0500, Mathieu Desnoyers wrote:
> Two new auxiliary vector entries are introduced for rseq without
> matching increment of the AT_VECTOR_SIZE_BASE, which causes failures
> with CONFIG_HARDENED_USERCOPY=y.
> 
> Reported-by: Nathan Chancellor <nathan@kernel.org>
> Link: https://lore.kernel.org/r/Y7XJKZhuU9VJZQ11@dev-arch.thelio-3990X
> Fixes: 317c8194e6ae ("rseq: Introduce feature size and alignment ELF auxiliary vector entries")
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

This resolves the boot failure with the configuration I tested:

Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  include/linux/auxvec.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/auxvec.h b/include/linux/auxvec.h
> index f68d0ec2d740..407f7005e6d6 100644
> --- a/include/linux/auxvec.h
> +++ b/include/linux/auxvec.h
> @@ -4,6 +4,6 @@
>  
>  #include <uapi/linux/auxvec.h>
>  
> -#define AT_VECTOR_SIZE_BASE 20 /* NEW_AUX_ENT entries in auxiliary table */
> +#define AT_VECTOR_SIZE_BASE 22 /* NEW_AUX_ENT entries in auxiliary table */
>    /* number of "#define AT_.*" above, minus {AT_NULL, AT_IGNORE, AT_NOTELF} */
>  #endif /* _LINUX_AUXVEC_H */
> -- 
> 2.25.1
>

Re: [RFC PATCH tip] rseq: Fix: Increase AT_VECTOR_SIZE_BASE to match rseq auxvec entries

Posted by Peter Zijlstra 2 years, 8 months ago

On Wed, Jan 04, 2023 at 12:24:09PM -0700, Nathan Chancellor wrote:
> On Wed, Jan 04, 2023 at 02:20:54PM -0500, Mathieu Desnoyers wrote:
> > Two new auxiliary vector entries are introduced for rseq without
> > matching increment of the AT_VECTOR_SIZE_BASE, which causes failures
> > with CONFIG_HARDENED_USERCOPY=y.
> > 
> > Reported-by: Nathan Chancellor <nathan@kernel.org>
> > Link: https://lore.kernel.org/r/Y7XJKZhuU9VJZQ11@dev-arch.thelio-3990X
> > Fixes: 317c8194e6ae ("rseq: Introduce feature size and alignment ELF auxiliary vector entries")
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> 
> This resolves the boot failure with the configuration I tested:
> 
> Tested-by: Nathan Chancellor <nathan@kernel.org>

Thanks!

[tip: sched/core] rseq: Increase AT_VECTOR_SIZE_BASE to match rseq auxvec entries

Posted by tip-bot2 for Mathieu Desnoyers 2 years, 8 months ago

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     28c8e088427ad30b4260953f3b6f908972b77c2d
Gitweb:        https://git.kernel.org/tip/28c8e088427ad30b4260953f3b6f908972b77c2d
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Wed, 04 Jan 2023 14:20:54 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 12 Jan 2023 11:22:22 +01:00

rseq: Increase AT_VECTOR_SIZE_BASE to match rseq auxvec entries

Two new auxiliary vector entries are introduced for rseq without
matching increment of the AT_VECTOR_SIZE_BASE, which causes failures
with CONFIG_HARDENED_USERCOPY=y.

Fixes: 317c8194e6ae ("rseq: Introduce feature size and alignment ELF auxiliary vector entries")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230104192054.34046-1-mathieu.desnoyers@efficios.com
---
 include/linux/auxvec.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/auxvec.h b/include/linux/auxvec.h
index f68d0ec..407f700 100644
--- a/include/linux/auxvec.h
+++ b/include/linux/auxvec.h
@@ -4,6 +4,6 @@
 
 #include <uapi/linux/auxvec.h>
 
-#define AT_VECTOR_SIZE_BASE 20 /* NEW_AUX_ENT entries in auxiliary table */
+#define AT_VECTOR_SIZE_BASE 22 /* NEW_AUX_ENT entries in auxiliary table */
   /* number of "#define AT_.*" above, minus {AT_NULL, AT_IGNORE, AT_NOTELF} */
 #endif /* _LINUX_AUXVEC_H */