| 1 | |
| 2 |
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| 3 | #include "dev.h"
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| 4 | #include "fuse_i.h"
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| 5 |
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| 6 | static int fuse_fill_creds(struct fuse_mount *fm, struct fuse_args *args,
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| 7 | const struct mnt_idmap *idmap)
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| 8 | {
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| 9 | struct fuse_conn *fc = fm->fc;
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| 10 | bool no_idmap = !fm->sb || (fm->sb->s_iflags & SB_I_NOIDMAP);
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| 11 | kuid_t fsuid = mapped_fsuid(idmap, fc->user_ns);
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| 12 | kgid_t fsgid = mapped_fsgid(idmap, fc->user_ns);
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| 13 |
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| 14 | args->pid = pid_nr_ns(task_pid(current), fc->pid_ns);
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| 15 |
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| 16 | if (args->force) {
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| 17 | if (args->nocreds)
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| 18 | return 0;
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| 19 |
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| 20 | if (no_idmap) {
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| 21 | args->uid = from_kuid_munged(fc->user_ns, current_fsuid());
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| 22 | args->gid = from_kgid_munged(fc->user_ns, current_fsgid());
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| 23 | } else {
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| 24 | args->uid = FUSE_INVALID_UIDGID;
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| 25 | args->gid = FUSE_INVALID_UIDGID;
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| 26 | }
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| 27 | return 0;
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| 28 | }
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| 29 |
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| 30 | WARN_ON(args->nocreds);
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| 31 | |
| 32 | * Keep the old behavior when idmappings support was not
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| 33 | * declared by a FUSE server.
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| 34 | *
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| 35 | * For those FUSE servers who support idmapped mounts, we send UID/GID
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| 36 | * only along with "inode creation" fuse requests, otherwise idmap ==
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| 37 | * &invalid_mnt_idmap and req->in.h.{u,g}id will be equal to
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| 38 | * FUSE_INVALID_UIDGID.
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| 39 |
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| 40 | if (no_idmap) {
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| 41 | fsuid = current_fsuid();
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| 42 | fsgid = current_fsgid();
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| 43 | }
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| 44 | args->uid = from_kuid(fc->user_ns, fsuid);
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| 45 | args->gid = from_kgid(fc->user_ns, fsgid);
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| 46 |
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| 47 | if (no_idmap && unlikely(args->uid == ((uid_t)-1) || args->gid == ((gid_t)-1)))
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| 48 | return -EOVERFLOW;
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| 49 |
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| 50 | return 0;
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| 51 | }
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| 52 |
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| 53 | static int fuse_req_prep(struct fuse_mount *fm, struct fuse_args *args,
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| 54 | const struct mnt_idmap *idmap)
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| 55 | {
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| 56 | if (!args->force && fm->fc->conn_error)
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| 57 | return -ECONNREFUSED;
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| 58 |
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| 59 | return fuse_fill_creds(fm, args, idmap);
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| 60 | }
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| 61 |
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| 62 | ssize_t __fuse_simple_request(const struct mnt_idmap *idmap, struct fuse_mount *fm,
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| 63 | struct fuse_args *args)
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| 64 | {
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| 65 | struct fuse_conn *fc = fm->fc;
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| 66 | int err = fuse_req_prep(fm, args, idmap);
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| 67 |
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| 68 | if (err)
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| 69 | return err;
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| 70 |
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| 71 | return fuse_chan_send(fc->chan, args);
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| 72 | }
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| 73 |
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| 74 | int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args, gfp_t gfp_flags)
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| 75 | {
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| 76 | struct fuse_conn *fc = fm->fc;
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| 77 | int err;
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| 78 |
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| 79 | WARN_ON(args->force && !args->nocreds);
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| 80 |
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| 81 | err = fuse_req_prep(fm, args, &invalid_mnt_idmap);
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| 82 | if (err)
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| 83 | return err;
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| 84 |
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| 85 | return fuse_chan_send_bg(fc->chan, args, gfp_flags);
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| 86 | }
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| 87 | EXPORT_SYMBOL_GPL(fuse_simple_background);
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| 88 |
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| 89 | int fuse_simple_notify_reply(struct fuse_mount *fm, struct fuse_args *args, u64 unique)
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| 90 | {
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| 91 | struct fuse_conn *fc = fm->fc;
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| 92 | int err;
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| 93 |
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| 94 | WARN_ON(args->force && !args->nocreds);
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| 95 |
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| 96 | err = fuse_req_prep(fm, args, &invalid_mnt_idmap);
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| 97 | if (err)
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| 98 | return err;
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| 99 |
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| 100 | return fuse_chan_send_notify_reply(fc->chan, args, unique);
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| 101 | }
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