From: Vivek Goyal vgoyal@redhat.com
mainline inclusion from mainline-v5.11-rc1 commit 643a666a89c358ef588d2b3ef9f2dc1efc421e61 category: perf bugzilla: https://gitee.com/openeuler/kernel/issues/I4SIR8
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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With FUSE_HANDLE_KILLPRIV_V2 support, server will need to kill suid/sgid/ security.capability on open(O_TRUNC), if server supports FUSE_ATOMIC_O_TRUNC.
But server needs to kill suid/sgid only if caller does not have CAP_FSETID. Given server does not have this information, client needs to send this info to server.
So add a flag FUSE_OPEN_KILL_SUIDGID to fuse_open_in request which tells server to kill suid/sgid (only if group execute is set).
This flag is added to the FUSE_OPEN request, as well as the FUSE_CREATE request if the create was non-exclusive, since that might result in an existing file being opened/truncated.
Signed-off-by: Vivek Goyal vgoyal@redhat.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Baokun Li libaokun1@huawei.com Reviewed-by: Hou Tao houtao1@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- fs/fuse/dir.c | 6 ++++++ fs/fuse/file.c | 6 ++++++ include/uapi/linux/fuse.h | 11 +++++++++-- 3 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index f7e02f8151a7..6ab3798da079 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -560,6 +560,12 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, inarg.flags = flags; inarg.mode = mode; inarg.umask = current_umask(); + + if (fm->fc->handle_killpriv_v2 && (flags & O_TRUNC) && + !(flags & O_EXCL) && !capable(CAP_FSETID)) { + inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID; + } + args.opcode = FUSE_CREATE; args.nodeid = get_node_id(dir); args.in_numargs = 2; diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 386c40478eee..e63ce8443c96 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -42,6 +42,12 @@ static int fuse_send_open(struct fuse_mount *fm, u64 nodeid, struct file *file, inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY); if (!fm->fc->atomic_o_trunc) inarg.flags &= ~O_TRUNC; + + if (fm->fc->handle_killpriv_v2 && + (inarg.flags & O_TRUNC) && !capable(CAP_FSETID)) { + inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID; + } + args.opcode = opcode; args.nodeid = nodeid; args.in_numargs = 1; diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 9eb96e0564be..98ca64d1beb6 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -178,6 +178,7 @@ * * 7.33 * - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID + * - add FUSE_OPEN_KILL_SUIDGID */
#ifndef _LINUX_FUSE_H @@ -444,6 +445,12 @@ struct fuse_file_lock { */ #define FUSE_ATTR_SUBMOUNT (1 << 0)
+/** + * Open flags + * FUSE_OPEN_KILL_SUIDGID: Kill suid and sgid if executable + */ +#define FUSE_OPEN_KILL_SUIDGID (1 << 0) + enum fuse_opcode { FUSE_LOOKUP = 1, FUSE_FORGET = 2, /* no reply */ @@ -605,14 +612,14 @@ struct fuse_setattr_in {
struct fuse_open_in { uint32_t flags; - uint32_t unused; + uint32_t open_flags; /* FUSE_OPEN_... */ };
struct fuse_create_in { uint32_t flags; uint32_t mode; uint32_t umask; - uint32_t padding; + uint32_t open_flags; /* FUSE_OPEN_... */ };
struct fuse_open_out {