unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
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io_uring: make sure accept honor rlimit nofile

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Just like commit 4022e7af86, this fixes the fact that
IORING_OP_ACCEPT ends up using get_unused_fd_flags(), which checks
current->signal->rlim[] for limits.

Add an extra argument to __sys_accept4_file() that allows us to pass
in the proper nofile limit, and grab it at request prep time.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2020-03-19 20:16:56 -06:00
parent 4022e7af86
commit 09952e3e78
3 changed files with 11 additions and 5 deletions
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5
fs/io_uring.c
View file

@ -343,6 +343,7 @@ struct io_accept {
struct sockaddr __user *addr;
int __user *addr_len;
int flags;
unsigned long nofile;
};
struct io_sync {
@ -3324,6 +3325,7 @@ static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
accept->flags = READ_ONCE(sqe->accept_flags);
accept->nofile = rlimit(RLIMIT_NOFILE);
return 0;
#else
return -EOPNOTSUPP;
@ -3340,7 +3342,8 @@ static int __io_accept(struct io_kiocb *req, struct io_kiocb **nxt,
file_flags = force_nonblock ? O_NONBLOCK : 0;
ret = __sys_accept4_file(req->file, file_flags, accept->addr,
accept->addr_len, accept->flags);
accept->addr_len, accept->flags,
accept->nofile);
if (ret == -EAGAIN && force_nonblock)
return -EAGAIN;
if (ret == -ERESTARTSYS)

3
include/linux/socket.h
View file

@ -401,7 +401,8 @@ extern int __sys_sendto(int fd, void __user *buff, size_t len,
int addr_len);
extern int __sys_accept4_file(struct file *file, unsigned file_flags,
struct sockaddr __user *upeer_sockaddr,
int __user *upeer_addrlen, int flags);
int __user *upeer_addrlen, int flags,
unsigned long nofile);
extern int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
int __user *upeer_addrlen, int flags);
extern int __sys_socket(int family, int type, int protocol);

8
net/socket.c
View file

@ -1707,7 +1707,8 @@ SYSCALL_DEFINE2(listen, int, fd, int, backlog)
int __sys_accept4_file(struct file *file, unsigned file_flags,
struct sockaddr __user *upeer_sockaddr,
int __user *upeer_addrlen, int flags)
int __user *upeer_addrlen, int flags,
unsigned long nofile)
{
struct socket *sock, *newsock;
struct file *newfile;
@ -1738,7 +1739,7 @@ int __sys_accept4_file(struct file *file, unsigned file_flags,
*/
__module_get(newsock->ops->owner);
newfd = get_unused_fd_flags(flags);
newfd = __get_unused_fd_flags(flags, nofile);
if (unlikely(newfd < 0)) {
err = newfd;
sock_release(newsock);
@ -1807,7 +1808,8 @@ int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
f = fdget(fd);
if (f.file) {
ret = __sys_accept4_file(f.file, 0, upeer_sockaddr,
upeer_addrlen, flags);
upeer_addrlen, flags,
rlimit(RLIMIT_NOFILE));
if (f.flags)
fput(f.file);
}