From: Pavel Begunkov asml.silence@gmail.com
stable inclusion from stable-v6.6.7 commit 5a33d385eb36991a91e3dddb189d8679e2aac2be category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8SSQ4
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
commit 705318a99a138c29a512a72c3e0043b3cd7f55f4 upstream.
File reference cycles have caused lots of problems for io_uring in the past, and it still doesn't work exactly right and races with unix_stream_read_generic(). The safest fix would be to completely disallow sending io_uring files via sockets via SCM_RIGHT, so there are no possible cycles invloving registered files and thus rendering SCM accounting on the io_uring side unnecessary.
Cc: stable@vger.kernel.org Fixes: 0091bfc81741b ("io_uring/af_unix: defer registered files gc to io_uring release") Reported-and-suggested-by: Jann Horn jannh@google.com Signed-off-by: Pavel Begunkov asml.silence@gmail.com Link: https://lore.kernel.org/r/c716c88321939156909cfa1bd8b0faaf1c804103.170186879... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- io_uring/rsrc.h | 7 ------- net/core/scm.c | 6 ++++++ 2 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h index 8625181fb87a..08ac0d8e07ef 100644 --- a/io_uring/rsrc.h +++ b/io_uring/rsrc.h @@ -77,17 +77,10 @@ int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file);
-#if defined(CONFIG_UNIX) -static inline bool io_file_need_scm(struct file *filp) -{ - return !!unix_get_socket(filp); -} -#else static inline bool io_file_need_scm(struct file *filp) { return false; } -#endif
static inline int io_scm_file_account(struct io_ring_ctx *ctx, struct file *file) diff --git a/net/core/scm.c b/net/core/scm.c index 880027ecf516..7dc47c17d863 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -26,6 +26,7 @@ #include <linux/nsproxy.h> #include <linux/slab.h> #include <linux/errqueue.h> +#include <linux/io_uring.h>
#include <linux/uaccess.h>
@@ -103,6 +104,11 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
if (fd < 0 || !(file = fget_raw(fd))) return -EBADF; + /* don't allow io_uring files */ + if (io_uring_get_socket(file)) { + fput(file); + return -EINVAL; + } *fpp++ = file; fpl->count++; }