diff options
Diffstat (limited to 'sys/kern/vfs_lookup.c')
| -rw-r--r-- | sys/kern/vfs_lookup.c | 60 |
1 files changed, 56 insertions, 4 deletions
diff --git a/sys/kern/vfs_lookup.c b/sys/kern/vfs_lookup.c index e9637a7f3e4..a57f6f99915 100644 --- a/sys/kern/vfs_lookup.c +++ b/sys/kern/vfs_lookup.c @@ -1,4 +1,4 @@ -/* $OpenBSD: vfs_lookup.c,v 1.76 2019/01/03 21:52:31 beck Exp $ */ +/* $OpenBSD: vfs_lookup.c,v 1.77 2019/05/13 22:55:27 beck Exp $ */ /* $NetBSD: vfs_lookup.c,v 1.17 1996/02/09 19:00:59 christos Exp $ */ /* @@ -61,6 +61,29 @@ void unveil_start_relative(struct proc *p, struct nameidata *ni); void unveil_check_component(struct proc *p, struct nameidata *ni, struct vnode *dp ); int unveil_check_final(struct proc *p, struct nameidata *ni); +int +component_push(struct componentname *cnp, char *component, size_t len) +{ + if (cnp->cn_rpi + len + 1 >= MAXPATHLEN) + return 0; + if (cnp->cn_rpi > 1) + cnp->cn_rpbuf[cnp->cn_rpi++] = '/'; + memcpy(cnp->cn_rpbuf + cnp->cn_rpi, component, len); + cnp->cn_rpi+=len; + cnp->cn_rpbuf[cnp->cn_rpi] = '\0'; + return 1; +} + +void +component_pop(struct componentname *cnp) +{ + while(cnp->cn_rpi && cnp->cn_rpbuf[cnp->cn_rpi] != '/' ) + cnp->cn_rpi--; + if (cnp->cn_rpi == 0 && cnp->cn_rpbuf[0] == '/') + cnp->cn_rpi++; + cnp->cn_rpbuf[cnp->cn_rpi] = '\0'; +} + void ndinitat(struct nameidata *ndp, u_long op, u_long flags, enum uio_seg segflg, int dirfd, const char *namep, struct proc *p) @@ -190,6 +213,11 @@ fail: if (cnp->cn_pnbuf[0] == '/') { dp = ndp->ni_rootdir; vref(dp); + if (cnp->cn_flags & REALPATH && cnp->cn_rpi == 0) { + cnp->cn_rpbuf[0] = '/'; + cnp->cn_rpbuf[1] = '\0'; + cnp->cn_rpi = 1; + } } else if (ndp->ni_dirfd == AT_FDCWD) { dp = fdp->fd_cdir; vref(dp); @@ -303,6 +331,13 @@ badlink: vref(dp); ndp->ni_unveil_match = NULL; unveil_check_component(p, ndp, dp); + if (cnp->cn_flags & REALPATH) { + cnp->cn_rpbuf[0] = '/'; + cnp->cn_rpbuf[1] = '\0'; + cnp->cn_rpi = 1; + } + } else if (cnp->cn_flags & REALPATH) { + component_pop(cnp); } } pool_put(&namei_pool, cnp->cn_pnbuf); @@ -441,6 +476,19 @@ dirloop: printf("{%s}: ", cnp->cn_nameptr); *cp = c; } #endif + if (cnp->cn_flags & REALPATH) { + size_t len = cp - cnp->cn_nameptr; + if (len == 2 && cnp->cn_nameptr[0] == '.' && + cnp->cn_nameptr[1] == '.') + component_pop(cnp); + else if (!(len == 1 && cnp->cn_nameptr[0] == '.')) { + if (!component_push(cnp, cnp->cn_nameptr, len)) { + error = ENAMETOOLONG; + goto bad; + } + } + } + ndp->ni_pathlen -= cnp->cn_namelen; ndp->ni_next = cp; /* @@ -529,10 +577,12 @@ dirloop: printf("not found\n"); #endif /* - * Allow for unveiling of a file in a directory - * where we don't have access to create it ourselves + * Allow for unveiling or realpath'ing a file in a + * directory where we don't have access to create it + * ourselves */ - if (ndp->ni_pledge == PLEDGE_UNVEIL && error == EACCES) + if ((ndp->ni_pledge == PLEDGE_UNVEIL || + (cnp->cn_flags & REALPATH)) && error == EACCES) error = EJUSTRETURN; if (error != EJUSTRETURN) @@ -808,3 +858,5 @@ bad: *vpp = NULL; return (error); } + + |