Commit cb3bc23361830872663395de112c2c76ff00be50

Authored by balrog
1 parent e856f2ad

Fix getgroups() with zero size parameter (Kirill Shutemov).

According to man page getgroups(2):

If size is zero, list is not modified, but the total number of
supplementary group IDs for the process is returned.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5266 c046a42c-6fe2-441c-8c8c-71466251a162
Showing 1 changed file with 4 additions and 0 deletions
linux-user/syscall.c
@@ -5247,6 +5247,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, @@ -5247,6 +5247,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
5247 5247
5248 grouplist = alloca(gidsetsize * sizeof(gid_t)); 5248 grouplist = alloca(gidsetsize * sizeof(gid_t));
5249 ret = get_errno(getgroups(gidsetsize, grouplist)); 5249 ret = get_errno(getgroups(gidsetsize, grouplist));
  5250 + if (gidsetsize == 0)
  5251 + break;
5250 if (!is_error(ret)) { 5252 if (!is_error(ret)) {
5251 target_grouplist = lock_user(VERIFY_WRITE, arg2, gidsetsize * 2, 0); 5253 target_grouplist = lock_user(VERIFY_WRITE, arg2, gidsetsize * 2, 0);
5252 if (!target_grouplist) 5254 if (!target_grouplist)
@@ -5397,6 +5399,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, @@ -5397,6 +5399,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
5397 5399
5398 grouplist = alloca(gidsetsize * sizeof(gid_t)); 5400 grouplist = alloca(gidsetsize * sizeof(gid_t));
5399 ret = get_errno(getgroups(gidsetsize, grouplist)); 5401 ret = get_errno(getgroups(gidsetsize, grouplist));
  5402 + if (gidsetsize == 0)
  5403 + break;
5400 if (!is_error(ret)) { 5404 if (!is_error(ret)) {
5401 target_grouplist = lock_user(VERIFY_WRITE, arg2, gidsetsize * 4, 0); 5405 target_grouplist = lock_user(VERIFY_WRITE, arg2, gidsetsize * 4, 0);
5402 if (!target_grouplist) { 5406 if (!target_grouplist) {