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  1. 15 4月, 2015 13 次提交
  3. 09 4月, 2015 3 次提交
  5. 07 4月, 2015 2 次提交
    • A
      ioctx_alloc(): fix vma (and file) leak on failure · deeb8525
      由 Al Viro 提交于 
      If we fail past the aio_setup_ring(), we need to destroy the
mapping.  We don't need to care about anybody having found ctx,
or added requests to it, since the last failure exit is exactly
the failure to make ctx visible to lookups.

Reproducer (based on one by Joe Mario <jmario@redhat.com>):

void count(char *p)
{
	char s[80];
	printf("%s: ", p);
	fflush(stdout);
	sprintf(s, "/bin/cat /proc/%d/maps|/bin/fgrep -c '/[aio] (deleted)'", getpid());
	system(s);
}

int main()
{
	io_context_t *ctx;
	int created, limit, i, destroyed;
	FILE *f;

	count("before");
	if ((f = fopen("/proc/sys/fs/aio-max-nr", "r")) == NULL)
		perror("opening aio-max-nr");
	else if (fscanf(f, "%d", &limit) != 1)
		fprintf(stderr, "can't parse aio-max-nr\n");
	else if ((ctx = calloc(limit, sizeof(io_context_t))) == NULL)
		perror("allocating aio_context_t array");
	else {
		for (i = 0, created = 0; i < limit; i++) {
			if (io_setup(1000, ctx + created) == 0)
				created++;
		}
		for (i = 0, destroyed = 0; i < created; i++)
			if (io_destroy(ctx[i]) == 0)
				destroyed++;
		printf("created %d, failed %d, destroyed %d\n",
			created, limit - created, destroyed);
		count("after");
	}
}
Found-by: NJoe Mario <jmario@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      deeb8525
    • A
      fix mremap() vs. ioctx_kill() race · b2edffdd
      由 Al Viro 提交于 
      teach ->mremap() method to return an error and have it fail for
aio mappings in process of being killed

Note that in case of ->mremap() failure we need to undo move_page_tables()
we'd already done; we could call ->mremap() first, but then the failure of
move_page_tables() would require undoing whatever _successful_ ->mremap()
has done, which would be a lot more headache in general.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      b2edffdd
  7. 03 4月, 2015 1 次提交
  9. 01 4月, 2015 8 次提交
  11. 31 3月, 2015 1 次提交
  13. 27 3月, 2015 1 次提交
  15. 26 3月, 2015 7 次提交
  17. 25 3月, 2015 2 次提交
  19. 22 3月, 2015 1 次提交
  21. 21 3月, 2015 1 次提交
    • D
      cifs: fix use-after-free bug in find_writable_file · e1e9bda2
      由 David Disseldorp 提交于 
      Under intermittent network outages, find_writable_file() is susceptible
to the following race condition, which results in a user-after-free in
the cifs_writepages code-path:

Thread 1                                        Thread 2
========                                        ========

inv_file = NULL
refind = 0
spin_lock(&cifs_file_list_lock)

// invalidHandle found on openFileList

inv_file = open_file
// inv_file->count currently 1

cifsFileInfo_get(inv_file)
// inv_file->count = 2

spin_unlock(&cifs_file_list_lock);

cifs_reopen_file()                            cifs_close()
// fails (rc != 0)                            ->cifsFileInfo_put()
                                       spin_lock(&cifs_file_list_lock)
                                       // inv_file->count = 1
                                       spin_unlock(&cifs_file_list_lock)

spin_lock(&cifs_file_list_lock);
list_move_tail(&inv_file->flist,
      &cifs_inode->openFileList);
spin_unlock(&cifs_file_list_lock);

cifsFileInfo_put(inv_file);
->spin_lock(&cifs_file_list_lock)

  // inv_file->count = 0
  list_del(&cifs_file->flist);
  // cleanup!!
  kfree(cifs_file);

  spin_unlock(&cifs_file_list_lock);

spin_lock(&cifs_file_list_lock);
++refind;
// refind = 1
goto refind_writable;

At this point we loop back through with an invalid inv_file pointer
and a refind value of 1. On second pass, inv_file is not overwritten on
openFileList traversal, and is subsequently dereferenced.
Signed-off-by: NDavid Disseldorp <ddiss@suse.de>
Reviewed-by: NJeff Layton <jlayton@samba.org>
CC: <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>
      e1e9bda2