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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-21 11:54:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-21 11:54:47 -0700
commit1ab7ea1f83d16489142bcfa1b7670ac7ca86cd81 (patch)
treee57f1ce4dc6dadb29611d4d7fde2a37d33087f48
parent6c1bae744d5a15108c412336d95f3c4e5db6aff4 (diff)
parent09952e3e7826119ddd4357c453d54bcc7ef25156 (diff)
Merge tag 'io_uring-5.6-20200320' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe: "Two different fixes in here: - Fix for a potential NULL pointer deref for links with async or drain marked (Pavel) - Fix for not properly checking RLIMIT_NOFILE for async punted operations. This affects openat/openat2, which were added this cycle, and accept4. I did a full audit of other cases where we might check current->signal->rlim[] and found only RLIMIT_FSIZE for buffered writes and fallocate. That one is fixed and queued for 5.7 and marked stable" * tag 'io_uring-5.6-20200320' of git://git.kernel.dk/linux-block: io_uring: make sure accept honor rlimit nofile io_uring: make sure openat/openat2 honor rlimit nofile io_uring: NULL-deref for IOSQE_{ASYNC,DRAIN}
-rw-r--r--fs/file.c7
-rw-r--r--fs/io_uring.c18
-rw-r--r--include/linux/file.h1
-rw-r--r--include/linux/socket.h3
-rw-r--r--net/socket.c8
5 files changed, 30 insertions, 7 deletions
diff --git a/fs/file.c b/fs/file.c
index a364e1a9b7e8..c8a4e4c86e55 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -540,9 +540,14 @@ static int alloc_fd(unsigned start, unsigned flags)
return __alloc_fd(current->files, start, rlimit(RLIMIT_NOFILE), flags);
}
+int __get_unused_fd_flags(unsigned flags, unsigned long nofile)
+{
+ return __alloc_fd(current->files, 0, nofile, flags);
+}
+
int get_unused_fd_flags(unsigned flags)
{
- return __alloc_fd(current->files, 0, rlimit(RLIMIT_NOFILE), flags);
+ return __get_unused_fd_flags(flags, rlimit(RLIMIT_NOFILE));
}
EXPORT_SYMBOL(get_unused_fd_flags);
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1b2517291b78..3affd96a98ba 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -343,6 +343,7 @@ struct io_accept {
struct sockaddr __user *addr;
int __user *addr_len;
int flags;
+ unsigned long nofile;
};
struct io_sync {
@@ -397,6 +398,7 @@ struct io_open {
struct filename *filename;
struct statx __user *buffer;
struct open_how how;
+ unsigned long nofile;
};
struct io_files_update {
@@ -2577,6 +2579,7 @@ static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return ret;
}
+ req->open.nofile = rlimit(RLIMIT_NOFILE);
req->flags |= REQ_F_NEED_CLEANUP;
return 0;
}
@@ -2618,6 +2621,7 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return ret;
}
+ req->open.nofile = rlimit(RLIMIT_NOFILE);
req->flags |= REQ_F_NEED_CLEANUP;
return 0;
}
@@ -2636,7 +2640,7 @@ static int io_openat2(struct io_kiocb *req, struct io_kiocb **nxt,
if (ret)
goto err;
- ret = get_unused_fd_flags(req->open.how.flags);
+ ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
if (ret < 0)
goto err;
@@ -3321,6 +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;
@@ -3337,7 +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)
@@ -4131,6 +4137,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
{
ssize_t ret = 0;
+ if (!sqe)
+ return 0;
+
if (io_op_defs[req->opcode].file_table) {
ret = io_grab_files(req);
if (unlikely(ret))
@@ -4907,6 +4916,11 @@ err_req:
if (sqe_flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK)) {
req->flags |= REQ_F_LINK;
INIT_LIST_HEAD(&req->link_list);
+
+ if (io_alloc_async_ctx(req)) {
+ ret = -EAGAIN;
+ goto err_req;
+ }
ret = io_req_defer_prep(req, sqe);
if (ret)
req->flags |= REQ_F_FAIL_LINK;
diff --git a/include/linux/file.h b/include/linux/file.h
index c6c7b24ea9f7..142d102f285e 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -85,6 +85,7 @@ extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
extern int replace_fd(unsigned fd, struct file *file, unsigned flags);
extern void set_close_on_exec(unsigned int fd, int flag);
extern bool get_close_on_exec(unsigned int fd);
+extern int __get_unused_fd_flags(unsigned flags, unsigned long nofile);
extern int get_unused_fd_flags(unsigned flags);
extern void put_unused_fd(unsigned int fd);
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 2d2313403101..15f3412d481e 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -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);
diff --git a/net/socket.c b/net/socket.c
index b79a05de7c6e..2eecf1517f76 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -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);
}