[v2] bsd-user mmap fixes

[PATCH v2 4/9] bsd-user/mmap.c: mmap return ENOMEM on overflow

Posted by Warner Losh 4 years, 4 months ago

mmap should return ENOMEM on len overflow rather than EINVAL. Return
EINVAL when len == 0 and ENOMEM when the rounded to a page length is 0.
Found by make check-tcg.

Signed-off-by: Warner Losh <imp@bsdimp.com>
---
 bsd-user/mmap.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index c40059d7fc..0acc2db712 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -454,11 +454,18 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
         goto fail;
     }
 
-    len = TARGET_PAGE_ALIGN(len);
     if (len == 0) {
         errno = EINVAL;
         goto fail;
     }
+
+    /* Check for overflows */
+    len = TARGET_PAGE_ALIGN(len);
+    if (len == 0) {
+        errno = ENOMEM;
+        goto fail;
+    }
+
     real_start = start & qemu_host_page_mask;
     host_offset = offset & qemu_host_page_mask;
 
-- 
2.32.0

Re: [PATCH v2 4/9] bsd-user/mmap.c: mmap return ENOMEM on overflow

Posted by Philippe Mathieu-Daudé 4 years, 4 months ago

On 9/22/21 06:56, Warner Losh wrote:
> mmap should return ENOMEM on len overflow rather than EINVAL. Return
> EINVAL when len == 0 and ENOMEM when the rounded to a page length is 0.
> Found by make check-tcg.
> 
> Signed-off-by: Warner Losh <imp@bsdimp.com>
> ---
>   bsd-user/mmap.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Re: [PATCH v2 4/9] bsd-user/mmap.c: mmap return ENOMEM on overflow

Posted by Richard Henderson 4 years, 4 months ago

On 9/21/21 9:56 PM, Warner Losh wrote:
> mmap should return ENOMEM on len overflow rather than EINVAL. Return
> EINVAL when len == 0 and ENOMEM when the rounded to a page length is 0.
> Found by make check-tcg.
> 
> Signed-off-by: Warner Losh<imp@bsdimp.com>
> ---
>   bsd-user/mmap.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~