diff mbox series

[v4,5/5] linux-user: Sanitize interp_info and, for mips only, init field fp_abi

Message ID 1556905846-14074-6-git-send-email-aleksandar.markovic@rt-rk.com (mailing list archive)
State New, archived
Headers show
Series linux-user: A set of miscellaneous patches | expand

Commit Message

Aleksandar Markovic May 3, 2019, 5:50 p.m. UTC 
From: Daniel Santos <daniel.santos@pobox.com>

Sanitize interp_info structure in load_elf_binary() and, for MIPS only,
init its field fp_abi to MIPS_ABI_FP_UNKNOWN. This fixes appearances of
"Unexpected FPU mode" message in some MIPS use cases. Currently, this
bug is a complete stopper for some MIPS binaries.

In load_elf_binary(), struct image_info interp_info is used without
being properly initialized. One result is that when the ELF's program
header doesn't contain an entry for the ABI flags, then the value of
the struct image_info's fp_abi field is set to whatever happened to
be in stack memory at the time.

Backporting to 4.0 and, if possible, to 3.1 is recommended.

Fixes: https://bugs.launchpad.net/qemu/+bug/1825002

Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 linux-user/elfload.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Laurent Vivier May 9, 2019, 7:26 p.m. UTC | #1 
On 03/05/2019 19:50, Aleksandar Markovic wrote:
> From: Daniel Santos <daniel.santos@pobox.com>
> 
> Sanitize interp_info structure in load_elf_binary() and, for MIPS only,
> init its field fp_abi to MIPS_ABI_FP_UNKNOWN. This fixes appearances of
> "Unexpected FPU mode" message in some MIPS use cases. Currently, this
> bug is a complete stopper for some MIPS binaries.
> 
> In load_elf_binary(), struct image_info interp_info is used without
> being properly initialized. One result is that when the ELF's program
> header doesn't contain an entry for the ABI flags, then the value of
> the struct image_info's fp_abi field is set to whatever happened to
> be in stack memory at the time.
> 
> Backporting to 4.0 and, if possible, to 3.1 is recommended.
> 
> Fixes: https://bugs.launchpad.net/qemu/+bug/1825002
> 
> Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
> Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>   linux-user/elfload.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index c1a2602..7f09d57 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -2698,6 +2698,11 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
>       char *elf_interpreter = NULL;
>       char *scratch;
>   
> +    memset(&interp_info, 0, sizeof(interp_info));
> +#ifdef TARGET_MIPS
> +    interp_info.fp_abi = MIPS_ABI_FP_UNKNOWN;
> +#endif
> +
>       info->start_mmap = (abi_ulong)ELF_START_MMAP;
>   
>       load_elf_image(bprm->filename, bprm->fd, info,
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
diff mbox series

Patch

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index c1a2602..7f09d57 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2698,6 +2698,11 @@  int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
     char *elf_interpreter = NULL;
     char *scratch;
 
+    memset(&interp_info, 0, sizeof(interp_info));
+#ifdef TARGET_MIPS
+    interp_info.fp_abi = MIPS_ABI_FP_UNKNOWN;
+#endif
+
     info->start_mmap = (abi_ulong)ELF_START_MMAP;
 
     load_elf_image(bprm->filename, bprm->fd, info,