[v4] grantpt: Get rid of alloca
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| redhat-pt-bot/TryBot-apply_patch |
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Patch applied to master at the time it was sent
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| redhat-pt-bot/TryBot-32bit |
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Build for i686
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| linaro-tcwg-bot/tcwg_glibc_build--master-arm |
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| linaro-tcwg-bot/tcwg_glibc_build--master-aarch64 |
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| linaro-tcwg-bot/tcwg_glibc_check--master-arm |
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| linaro-tcwg-bot/tcwg_glibc_check--master-aarch64 |
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Commit Message
Replace alloca with a scratch_buffer to avoid potential stack overflows.
---
Changes since v3:
* Explicitly set the retval for scratch_buffer_set_array_size failure.
sysdeps/unix/grantpt.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
Comments
Applied, thanks!
Joe Simmons-Talbott, le mar. 13 juin 2023 15:16:31 -0400, a ecrit:
> Replace alloca with a scratch_buffer to avoid potential stack overflows.
> ---
> Changes since v3:
> * Explicitly set the retval for scratch_buffer_set_array_size failure.
>
> sysdeps/unix/grantpt.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/sysdeps/unix/grantpt.c b/sysdeps/unix/grantpt.c
> index 38fce52576..226e7adb75 100644
> --- a/sysdeps/unix/grantpt.c
> +++ b/sysdeps/unix/grantpt.c
> @@ -20,6 +20,7 @@
> #include <fcntl.h>
> #include <grp.h>
> #include <limits.h>
> +#include <scratch_buffer.h>
> #include <stdlib.h>
> #include <string.h>
> #include <sys/resource.h>
> @@ -147,10 +148,19 @@ grantpt (int fd)
> /* `sysconf' does not support _SC_GETGR_R_SIZE_MAX.
> Try a moderate value. */
> grbuflen = 1024;
> - grtmpbuf = (char *) __alloca (grbuflen);
> + struct scratch_buffer sbuf;
> + scratch_buffer_init (&sbuf);
> + if (!scratch_buffer_set_array_size (&sbuf, 1, grbuflen))
> + {
> + retval = -1;
> + goto cleanup;
> + }
> + grtmpbuf = sbuf.data;
> __getgrnam_r (TTY_GROUP, &grbuf, grtmpbuf, grbuflen, &p);
> if (p != NULL)
> tty_gid = p->gr_gid;
> +
> + scratch_buffer_free(&sbuf);
> }
> gid_t gid = tty_gid == -1 ? __getgid () : tty_gid;
>
> --
> 2.39.2
>
@@ -20,6 +20,7 @@
#include <fcntl.h>
#include <grp.h>
#include <limits.h>
+#include <scratch_buffer.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
@@ -147,10 +148,19 @@ grantpt (int fd)
/* `sysconf' does not support _SC_GETGR_R_SIZE_MAX.
Try a moderate value. */
grbuflen = 1024;
- grtmpbuf = (char *) __alloca (grbuflen);
+ struct scratch_buffer sbuf;
+ scratch_buffer_init (&sbuf);
+ if (!scratch_buffer_set_array_size (&sbuf, 1, grbuflen))
+ {
+ retval = -1;
+ goto cleanup;
+ }
+ grtmpbuf = sbuf.data;
__getgrnam_r (TTY_GROUP, &grbuf, grtmpbuf, grbuflen, &p);
if (p != NULL)
tty_gid = p->gr_gid;
+
+ scratch_buffer_free(&sbuf);
}
gid_t gid = tty_gid == -1 ? __getgid () : tty_gid;