From: Thayne Harbaugh <thayne@c2.net>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [BUG][PATCH] execve processesing NULL args
Date: Tue, 11 Dec 2007 09:34:03 -0700 [thread overview]
Message-ID: <1197390843.2947.41.camel@phantasm.home.enterpriseandprosperity.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 98 bytes --]
Here's a patch to avoid processing NULL args in execve. It prevents
trying to dereference NULL.
[-- Attachment #2: 50_execve_null_args.patch --]
[-- Type: text/x-patch, Size: 2178 bytes --]
Index: qemu/linux-user/syscall.c
===================================================================
--- qemu.orig/linux-user/syscall.c 2007-11-19 20:45:20.000000000 -0700
+++ qemu/linux-user/syscall.c 2007-11-19 20:48:54.000000000 -0700
@@ -3515,7 +3515,7 @@
argc = 0;
guest_argp = arg2;
- for (gp = guest_argp; ; gp += sizeof(abi_ulong)) {
+ for (gp = guest_argp; gp; gp += sizeof(abi_ulong)) {
if (get_user_ual(addr, gp))
goto efault;
if (!addr)
@@ -3524,7 +3524,7 @@
}
envc = 0;
guest_envp = arg3;
- for (gp = guest_envp; ; gp += sizeof(abi_ulong)) {
+ for (gp = guest_envp; gp; gp += sizeof(abi_ulong)) {
if (get_user_ual(addr, gp))
goto efault;
if (!addr)
@@ -3535,7 +3535,7 @@
argp = alloca((argc + 1) * sizeof(void *));
envp = alloca((envc + 1) * sizeof(void *));
- for (gp = guest_argp, q = argp; ;
+ for (gp = guest_argp, q = argp; gp;
gp += sizeof(abi_ulong), q++) {
if (get_user_ual(addr, gp))
goto execve_efault;
@@ -3546,7 +3546,7 @@
}
*q = NULL;
- for (gp = guest_envp, q = envp; ;
+ for (gp = guest_envp, q = envp; gp;
gp += sizeof(abi_ulong), q++) {
if (get_user_ual(addr, gp))
goto execve_efault;
@@ -3568,14 +3568,14 @@
ret = -TARGET_EFAULT;
execve_end:
- for (gp = guest_argp, q = argp; *q;
+ for (gp = guest_argp, q = argp; gp && *q;
gp += sizeof(abi_ulong), q++) {
if (get_user_ual(addr, gp)
|| !addr)
break;
unlock_user(*q, addr, 0);
}
- for (gp = guest_envp, q = envp; *q;
+ for (gp = guest_envp, q = envp; gp && *q;
gp += sizeof(abi_ulong), q++) {
if (get_user_ual(addr, gp)
|| !addr)
reply other threads:[~2007-12-11 16:43 UTC|newest]
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