35d955c598
[ Upstream commit a8b98c808eab3ec8f1b5a64be967b0f4af4cae43 ] Reporting event->pid should depend on the privileges of the user that initialized the group, not the privileges of the user reading the events. Use an internal group flag FANOTIFY_UNPRIV to record the fact that the group was initialized by an unprivileged user. To be on the safe side, the premissions to setup filesystem and mount marks now require that both the user that initialized the group and the user setting up the mark have CAP_SYS_ADMIN. Link: https://lore.kernel.org/linux-fsdevel/CAOQ4uxiA77_P5vtv7e83g0+9d7B5W9ZTE4GfQEYbWmfT1rA=VA@mail.gmail.com/ Fixes: 7cea2a3c505e ("fanotify: support limited functionality for unprivileged users") Cc: <Stable@vger.kernel.org> # v5.12+ Link: https://lore.kernel.org/r/20210524135321.2190062-1-amir73il@gmail.com Reviewed-by: Matthew Bobrowski <repnop@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
150 lines
4 KiB
C
Executable file
150 lines
4 KiB
C
Executable file
// SPDX-License-Identifier: GPL-2.0
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/fsnotify_backend.h>
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#include <linux/idr.h>
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#include <linux/init.h>
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#include <linux/inotify.h>
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#include <linux/fanotify.h>
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#include <linux/kernel.h>
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#include <linux/namei.h>
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#include <linux/sched.h>
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#include <linux/types.h>
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#include <linux/seq_file.h>
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#include <linux/exportfs.h>
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#include "inotify/inotify.h"
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#include "fdinfo.h"
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#include "fsnotify.h"
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#if defined(CONFIG_PROC_FS)
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#if defined(CONFIG_INOTIFY_USER) || defined(CONFIG_FANOTIFY)
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static void show_fdinfo(struct seq_file *m, struct file *f,
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void (*show)(struct seq_file *m,
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struct fsnotify_mark *mark))
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{
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struct fsnotify_group *group = f->private_data;
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struct fsnotify_mark *mark;
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mutex_lock(&group->mark_mutex);
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list_for_each_entry(mark, &group->marks_list, g_list) {
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show(m, mark);
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if (seq_has_overflowed(m))
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break;
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}
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mutex_unlock(&group->mark_mutex);
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}
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#if defined(CONFIG_EXPORTFS)
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static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
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{
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struct {
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struct file_handle handle;
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u8 pad[MAX_HANDLE_SZ];
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} f;
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int size, ret, i;
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f.handle.handle_bytes = sizeof(f.pad);
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size = f.handle.handle_bytes >> 2;
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ret = exportfs_encode_inode_fh(inode, (struct fid *)f.handle.f_handle, &size, NULL);
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if ((ret == FILEID_INVALID) || (ret < 0)) {
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WARN_ONCE(1, "Can't encode file handler for inotify: %d\n", ret);
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return;
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}
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f.handle.handle_type = ret;
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f.handle.handle_bytes = size * sizeof(u32);
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seq_printf(m, "fhandle-bytes:%x fhandle-type:%x f_handle:",
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f.handle.handle_bytes, f.handle.handle_type);
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for (i = 0; i < f.handle.handle_bytes; i++)
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seq_printf(m, "%02x", (int)f.handle.f_handle[i]);
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}
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#else
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static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
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{
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}
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#endif
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#ifdef CONFIG_INOTIFY_USER
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static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
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{
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struct inotify_inode_mark *inode_mark;
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struct inode *inode;
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if (mark->connector->type != FSNOTIFY_OBJ_TYPE_INODE)
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return;
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inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
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inode = igrab(fsnotify_conn_inode(mark->connector));
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if (inode) {
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seq_printf(m, "inotify wd:%x ino:%lx sdev:%x mask:%x ignored_mask:0 ",
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inode_mark->wd, inode->i_ino, inode->i_sb->s_dev,
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inotify_mark_user_mask(mark));
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show_mark_fhandle(m, inode);
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seq_putc(m, '\n');
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iput(inode);
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}
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}
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void inotify_show_fdinfo(struct seq_file *m, struct file *f)
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{
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show_fdinfo(m, f, inotify_fdinfo);
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}
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#endif /* CONFIG_INOTIFY_USER */
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#ifdef CONFIG_FANOTIFY
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static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
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{
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unsigned int mflags = 0;
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struct inode *inode;
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if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
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mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
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if (mark->connector->type == FSNOTIFY_OBJ_TYPE_INODE) {
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inode = igrab(fsnotify_conn_inode(mark->connector));
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if (!inode)
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return;
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seq_printf(m, "fanotify ino:%lx sdev:%x mflags:%x mask:%x ignored_mask:%x ",
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inode->i_ino, inode->i_sb->s_dev,
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mflags, mark->mask, mark->ignored_mask);
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show_mark_fhandle(m, inode);
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seq_putc(m, '\n');
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iput(inode);
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} else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
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struct mount *mnt = fsnotify_conn_mount(mark->connector);
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seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",
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mnt->mnt_id, mflags, mark->mask, mark->ignored_mask);
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} else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_SB) {
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struct super_block *sb = fsnotify_conn_sb(mark->connector);
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seq_printf(m, "fanotify sdev:%x mflags:%x mask:%x ignored_mask:%x\n",
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sb->s_dev, mflags, mark->mask, mark->ignored_mask);
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}
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}
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void fanotify_show_fdinfo(struct seq_file *m, struct file *f)
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{
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struct fsnotify_group *group = f->private_data;
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seq_printf(m, "fanotify flags:%x event-flags:%x\n",
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group->fanotify_data.flags & FANOTIFY_INIT_FLAGS,
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group->fanotify_data.f_flags);
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show_fdinfo(m, f, fanotify_fdinfo);
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}
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#endif /* CONFIG_FANOTIFY */
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#endif /* CONFIG_INOTIFY_USER || CONFIG_FANOTIFY */
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#endif /* CONFIG_PROC_FS */
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