diff --git a/fs/select.c b/fs/select.c index 0ee55af1a55c..11a3b1312abe 100644 --- a/fs/select.c +++ b/fs/select.c @@ -839,7 +839,7 @@ SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg) struct poll_list { struct poll_list *next; - int len; + unsigned int len; struct pollfd entries[]; }; @@ -975,14 +975,15 @@ static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, struct timespec64 *end_time) { struct poll_wqueues table; - int err = -EFAULT, fdcount, len; + int err = -EFAULT, fdcount; /* Allocate small arguments on the stack to save memory and be faster - use long to make sure the buffer is aligned properly on 64 bit archs to avoid unaligned access */ long stack_pps[POLL_STACK_ALLOC/sizeof(long)]; struct poll_list *const head = (struct poll_list *)stack_pps; struct poll_list *walk = head; - unsigned long todo = nfds; + unsigned int todo = nfds; + unsigned int len; if (nfds > rlimit(RLIMIT_NOFILE)) return -EINVAL; @@ -998,9 +999,9 @@ static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, sizeof(struct pollfd) * walk->len)) goto out_fds; - todo -= walk->len; - if (!todo) + if (walk->len >= todo) break; + todo -= walk->len; len = min(todo, POLLFD_PER_PAGE); walk = walk->next = kmalloc(struct_size(walk, entries, len), @@ -1020,7 +1021,7 @@ static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, for (walk = head; walk; walk = walk->next) { struct pollfd *fds = walk->entries; - int j; + unsigned int j; for (j = walk->len; j; fds++, ufds++, j--) unsafe_put_user(fds->revents, &ufds->revents, Efault);