lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] fix RLIM_NOFILE handling

Browse Source 
* dup2() should return -EBADF on exceeded sysctl_nr_open
* dup() should *not* return -EINVAL even if you have rlimit set to 0;
  it should get -EMFILE instead.

Check for orig_start exceeding rlimit taken to sys_fcntl().
Failing expand_files() in dup{2,3}() now gets -EMFILE remapped to -EBADF.
Consequently, remaining checks for rlimit are taken to expand_files().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2008-07-26 16:01:20 -04:00
parent 6c5d0512a0
commit 4e1e018ecc
3 changed files with 15 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
fs/fcntl.c
View File

@@ -64,11 +64,6 @@ static int locate_fd(unsigned int orig_start, int cloexec)
struct fdtable *fdt;
spin_lock(&files->file_lock);
error = -EINVAL;
if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
goto out;
repeat:
fdt = files_fdtable(files);
/*
@@ -83,10 +78,6 @@ repeat:
if (start < fdt->max_fds)
newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
fdt->max_fds, start);
error = -EMFILE;
if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
goto out;
error = expand_files(files, newfd);
if (error < 0)
@@ -141,13 +132,14 @@ asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags)
spin_lock(&files->file_lock);
if (!(file = fcheck(oldfd)))
goto out_unlock;
if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
goto out_unlock;
get_file(file); /* We are now finished with oldfd */
err = expand_files(files, newfd);
if (err < 0)
if (unlikely(err < 0)) {
if (err == -EMFILE)
err = -EBADF;
goto out_fput;
}
/* To avoid races with open() and dup(), we will mark the fd as
* in-use in the open-file bitmap throughout the entire dup2()
@@ -328,6 +320,8 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
switch (cmd) {
case F_DUPFD:
case F_DUPFD_CLOEXEC:
if (arg >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
break;
get_file(filp);
err = dupfd(filp, arg, cmd == F_DUPFD_CLOEXEC);
break;