Eric Lee / smarc-fsl-linux-kernel

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Commit c2132c1bc73d9a279cec148f74ea709c960b3d89

Authored by Anatol Pomozov
Committed by Miklos Szeredi
1 parent fb05f41f5f

Do not use RCU for current process credentials 

Commit c69e8d9c0 added rcu lock to fuse/dir.c It was assuming
that 'task' is some other process but in fact this parameter always
equals to 'current'. Inline this parameter to make it more readable
and remove RCU lock as it is not needed when access current process
credentials.

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

Showing 4 changed files with 13 additions and 17 deletions Side-by-side Diff

... ... @@ -985,7 +985,7 @@
985 985  
986 986 /*
987 987 * Calling into a user-controlled filesystem gives the filesystem
988   - * daemon ptrace-like capabilities over the requester process. This
  988 + * daemon ptrace-like capabilities over the current process. This
989 989 * means, that the filesystem daemon is able to record the exact
990 990 * filesystem operations performed, and can also control the behavior
991 991 * of the requester process in otherwise impossible ways. For example
992 992  
993 993  
994 994  
995 995  
... ... @@ -996,27 +996,23 @@
996 996 * for which the owner of the mount has ptrace privilege. This
997 997 * excludes processes started by other users, suid or sgid processes.
998 998 */
999   -int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
  999 +int fuse_allow_current_process(struct fuse_conn *fc)
1000 1000 {
1001 1001 const struct cred *cred;
1002   - int ret;
1003 1002  
1004 1003 if (fc->flags & FUSE_ALLOW_OTHER)
1005 1004 return 1;
1006 1005  
1007   - rcu_read_lock();
1008   - ret = 0;
1009   - cred = __task_cred(task);
  1006 + cred = current_cred();
1010 1007 if (uid_eq(cred->euid, fc->user_id) &&
1011 1008 uid_eq(cred->suid, fc->user_id) &&
1012 1009 uid_eq(cred->uid, fc->user_id) &&
1013 1010 gid_eq(cred->egid, fc->group_id) &&
1014 1011 gid_eq(cred->sgid, fc->group_id) &&
1015 1012 gid_eq(cred->gid, fc->group_id))
1016   - ret = 1;
1017   - rcu_read_unlock();
  1013 + return 1;
1018 1014  
1019   - return ret;
  1015 + return 0;
1020 1016 }
1021 1017  
1022 1018 static int fuse_access(struct inode *inode, int mask)
... ... @@ -1077,7 +1073,7 @@
1077 1073 bool refreshed = false;
1078 1074 int err = 0;
1079 1075  
1080   - if (!fuse_allow_task(fc, current))
  1076 + if (!fuse_allow_current_process(fc))
1081 1077 return -EACCES;
1082 1078  
1083 1079 /*
... ... @@ -1544,7 +1540,7 @@
1544 1540 loff_t oldsize;
1545 1541 int err;
1546 1542  
1547   - if (!fuse_allow_task(fc, current))
  1543 + if (!fuse_allow_current_process(fc))
1548 1544 return -EACCES;
1549 1545  
1550 1546 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
... ... @@ -1653,7 +1649,7 @@
1653 1649 struct inode *inode = entry->d_inode;
1654 1650 struct fuse_conn *fc = get_fuse_conn(inode);
1655 1651  
1656   - if (!fuse_allow_task(fc, current))
  1652 + if (!fuse_allow_current_process(fc))
1657 1653 return -EACCES;
1658 1654  
1659 1655 return fuse_update_attributes(inode, stat, NULL, NULL);
... ... @@ -1756,7 +1752,7 @@
1756 1752 struct fuse_getxattr_out outarg;
1757 1753 ssize_t ret;
1758 1754  
1759   - if (!fuse_allow_task(fc, current))
  1755 + if (!fuse_allow_current_process(fc))
1760 1756 return -EACCES;
1761 1757  
1762 1758 if (fc->no_listxattr)
... ... @@ -2082,7 +2082,7 @@
2082 2082 struct inode *inode = file->f_dentry->d_inode;
2083 2083 struct fuse_conn *fc = get_fuse_conn(inode);
2084 2084  
2085   - if (!fuse_allow_task(fc, current))
  2085 + if (!fuse_allow_current_process(fc))
2086 2086 return -EACCES;
2087 2087  
2088 2088 if (is_bad_inode(inode))
... ... @@ -774,9 +774,9 @@
774 774 int fuse_valid_type(int m);
775 775  
776 776 /**
777   - * Is task allowed to perform filesystem operation?
  777 + * Is current process allowed to perform filesystem operation?
778 778 */
779   -int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task);
  779 +int fuse_allow_current_process(struct fuse_conn *fc);
780 780  
781 781 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
782 782  
... ... @@ -408,7 +408,7 @@
408 408 struct fuse_statfs_out outarg;
409 409 int err;
410 410  
411   - if (!fuse_allow_task(fc, current)) {
  411 + if (!fuse_allow_current_process(fc)) {
412 412 buf->f_type = FUSE_SUPER_MAGIC;
413 413 return 0;
414 414 }