From 1fc0f78ca9f311c6277e2f1b7655bb4d43ceb311 Mon Sep 17 00:00:00 2001 From: Al Viro <viro@zeniv.linux.org.uk> Date: Mon, 20 Jun 2011 18:59:02 -0400 Subject: ->permission() sanitizing: MAY_NOT_BLOCK Duplicate the flags argument into mask bitmap. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- fs/namei.c | 7 +++++-- fs/proc/proc_sysctl.c | 2 +- include/linux/fs.h | 1 + 3 files changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index c5af0f3..723a3fe 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -318,13 +318,16 @@ static inline int exec_permission(struct inode *inode, unsigned int flags) { int ret; struct user_namespace *ns = inode_userns(inode); + int mask = MAY_EXEC; + if (flags & IPERM_FLAG_RCU) + mask |= MAY_NOT_BLOCK; if (inode->i_op->permission) { - ret = inode->i_op->permission(inode, MAY_EXEC, flags); + ret = inode->i_op->permission(inode, mask, flags); if (likely(!ret)) goto ok; } else { - ret = acl_permission_check(inode, MAY_EXEC, flags); + ret = acl_permission_check(inode, mask, flags); if (likely(!ret)) goto ok; if (ret != -EACCES) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index d167de3..349b22f 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -316,7 +316,7 @@ static int proc_sys_permission(struct inode *inode, int mask,unsigned int flags) if (!table) /* global root - r-xr-xr-x */ error = mask & MAY_WRITE ? -EACCES : 0; else /* Use the permissions on the sysctl table entry */ - error = sysctl_perm(head->root, table, mask); + error = sysctl_perm(head->root, table, mask & ~MAY_NOT_BLOCK); sysctl_head_finish(head); return error; diff --git a/include/linux/fs.h b/include/linux/fs.h index 0c15d5e..60c1fe6 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -63,6 +63,7 @@ struct inodes_stat_t { #define MAY_ACCESS 16 #define MAY_OPEN 32 #define MAY_CHDIR 64 +#define MAY_NOT_BLOCK 128 /* called from RCU mode, don't block */ /* * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond -- cgit v1.1