diff options
| author | Jiexun Wang <wangjiexun2025@gmail.com> | 2026-04-07 11:00:14 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-04-09 05:33:52 +0300 |
| commit | 39897df386376912d561d4946499379effa1e7ef (patch) | |
| tree | 2a473c5d11438c9071e90d7fc0804cd900ff6626 /net | |
| parent | 8e2760eaab778494fc1fa257031e0e1799647f46 (diff) | |
| download | linux-39897df386376912d561d4946499379effa1e7ef.tar.xz | |
af_unix: read UNIX_DIAG_VFS data under unix_state_lock
Exact UNIX diag lookups hold a reference to the socket, but not to
u->path. Meanwhile, unix_release_sock() clears u->path under
unix_state_lock() and drops the path reference after unlocking.
Read the inode and device numbers for UNIX_DIAG_VFS while holding
unix_state_lock(), then emit the netlink attribute after dropping the
lock.
This keeps the VFS data stable while the reply is being built.
Fixes: 5f7b0569460b ("unix_diag: Unix inode info NLA")
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Tested-by: Ren Wei <enjou1224z@gmail.com>
Signed-off-by: Jiexun Wang <wangjiexun2025@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260407080015.1744197-1-n05ec@lzu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/unix/diag.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/net/unix/diag.c b/net/unix/diag.c index ca3473026151..c9c1e51c4419 100644 --- a/net/unix/diag.c +++ b/net/unix/diag.c @@ -28,18 +28,23 @@ static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb) static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb) { - struct dentry *dentry = unix_sk(sk)->path.dentry; + struct unix_diag_vfs uv; + struct dentry *dentry; + bool have_vfs = false; + unix_state_lock(sk); + dentry = unix_sk(sk)->path.dentry; if (dentry) { - struct unix_diag_vfs uv = { - .udiag_vfs_ino = d_backing_inode(dentry)->i_ino, - .udiag_vfs_dev = dentry->d_sb->s_dev, - }; - - return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv); + uv.udiag_vfs_ino = d_backing_inode(dentry)->i_ino; + uv.udiag_vfs_dev = dentry->d_sb->s_dev; + have_vfs = true; } + unix_state_unlock(sk); - return 0; + if (!have_vfs) + return 0; + + return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv); } static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb) |