Re: [PATCH v2 2/2] linux-user: sigprocmask check read perms first

[Laurent Vivier]

Le 26/01/2022 à 18:58, Patrick Venture a écrit :

Linux kernel now checks the read permissions before validating `how`

Suggested-by: Laurent Vivier 
Signed-off-by: Patrick Venture 


Reviewed-by: Laurent Vivier 


---
  linux-user/syscall.c | 12 +++-
  1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 34bd819e38..210483d4e4 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -9465,6 +9465,13 @@ static abi_long do_syscall1(void *cpu_env, int num, 
abi_long arg1,
  int how;
  
  if (arg2) {

+p = lock_user(VERIFY_READ, arg2, sizeof(target_sigset_t), 1));
+if (!p) {
+return -TARGET_EFAULT;
+}
+target_to_host_old_sigset(, p);
+unlock_user(p, arg2, 0);
+set_ptr = 
  switch (arg1) {
  case TARGET_SIG_BLOCK:
  how = SIG_BLOCK;
@@ -9478,11 +9485,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
abi_long arg1,
  default:
  return -TARGET_EINVAL;
  }
-if (!(p = lock_user(VERIFY_READ, arg2, 
sizeof(target_sigset_t), 1)))
-return -TARGET_EFAULT;
-target_to_host_old_sigset(, p);
-unlock_user(p, arg2, 0);
-set_ptr = 
  } else {
  how = 0;
  set_ptr = NULL;

[PATCH v2 2/2] linux-user: sigprocmask check read perms first

[Patrick Venture]

Linux kernel now checks the read permissions before validating `how`

Suggested-by: Laurent Vivier 
Signed-off-by: Patrick Venture 
---
 linux-user/syscall.c | 12 +++-
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 34bd819e38..210483d4e4 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -9465,6 +9465,13 @@ static abi_long do_syscall1(void *cpu_env, int num, 
abi_long arg1,
 int how;
 
 if (arg2) {
+p = lock_user(VERIFY_READ, arg2, sizeof(target_sigset_t), 1));
+if (!p) {
+return -TARGET_EFAULT;
+}
+target_to_host_old_sigset(, p);
+unlock_user(p, arg2, 0);
+set_ptr = 
 switch (arg1) {
 case TARGET_SIG_BLOCK:
 how = SIG_BLOCK;
@@ -9478,11 +9485,6 @@ static abi_long do_syscall1(void *cpu_env, int num, 
abi_long arg1,
 default:
 return -TARGET_EINVAL;
 }
-if (!(p = lock_user(VERIFY_READ, arg2, 
sizeof(target_sigset_t), 1)))
-return -TARGET_EFAULT;
-target_to_host_old_sigset(, p);
-unlock_user(p, arg2, 0);
-set_ptr = 
 } else {
 how = 0;
 set_ptr = NULL;
-- 
2.35.0.rc0.227.g00780c9af4-goog