diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/imgact_shell.c | 28 | ||||
| -rw-r--r-- | sys/sys/param.h | 2 |
2 files changed, 17 insertions, 13 deletions
diff --git a/sys/kern/imgact_shell.c b/sys/kern/imgact_shell.c index d0ef87c..0dc9299 100644 --- a/sys/kern/imgact_shell.c +++ b/sys/kern/imgact_shell.c @@ -46,13 +46,18 @@ __FBSDID("$FreeBSD$"); /* * At the time of this writing, MAXSHELLCMDLEN == PAGE_SIZE. This is * significant because the caller has only mapped in one page of the - * file we're reading. This code should be changed to know how to - * read in the second page, but I'm not doing that just yet... + * file we're reading. */ #if MAXSHELLCMDLEN > PAGE_SIZE #error "MAXSHELLCMDLEN is larger than a single page!" #endif +/* + * MAXSHELLCMDLEN must be at least MAXINTERP plus the size of the `#!' + * prefix and terminating newline. + */ +CTASSERT(MAXSHELLCMDLEN >= MAXINTERP + 3); + /** * Shell interpreter image activator. An interpreter name beginning at * imgp->args->begin_argv is the minimal successful exit requirement. @@ -98,20 +103,20 @@ exec_shell_imgact(imgp) const char *image_header = imgp->image_header; const char *ihp, *interpb, *interpe, *maxp, *optb, *opte, *fname; int error, offset; - size_t length, clength; + size_t length; struct vattr vattr; struct sbuf *sname; /* a shell script? */ - if (((const short *) image_header)[0] != SHELLMAGIC) - return(-1); + if (((const short *)image_header)[0] != SHELLMAGIC) + return (-1); /* * Don't allow a shell script to be the shell for a shell * script. :-) */ if (imgp->interpreted) - return(ENOEXEC); + return (ENOEXEC); imgp->interpreted = 1; @@ -127,12 +132,9 @@ exec_shell_imgact(imgp) /* * Copy shell name and arguments from image_header into a string - * buffer. Remember that the caller has mapped only the - * first page of the file into memory. + * buffer. */ - clength = (vattr.va_size > PAGE_SIZE) ? PAGE_SIZE : vattr.va_size; - - maxp = &image_header[clength]; + maxp = &image_header[MIN(vattr.va_size, MAXSHELLCMDLEN)]; ihp = &image_header[2]; /* @@ -149,7 +151,7 @@ exec_shell_imgact(imgp) interpe = ihp; if (interpb == interpe) return (ENOEXEC); - if ((interpe - interpb) >= MAXSHELLCMDLEN) + if (interpe - interpb >= MAXINTERP) return (ENAMETOOLONG); /* @@ -163,6 +165,8 @@ exec_shell_imgact(imgp) while (ihp < maxp && ((*ihp != '\n') && (*ihp != '\0'))) ihp++; opte = ihp; + if (opte == maxp) + return (ENOEXEC); while (--ihp > optb && ((*ihp == ' ') || (*ihp == '\t'))) opte = ihp; diff --git a/sys/sys/param.h b/sys/sys/param.h index 8ca03f3..63ad008 100644 --- a/sys/sys/param.h +++ b/sys/sys/param.h @@ -73,7 +73,7 @@ #include <sys/syslimits.h> #define MAXCOMLEN 19 /* max command name remembered */ -#define MAXINTERP 32 /* max interpreter file name length */ +#define MAXINTERP PATH_MAX /* max interpreter file name length */ #define MAXLOGNAME 17 /* max login name length (incl. NUL) */ #define MAXUPRC CHILD_MAX /* max simultaneous processes */ #define NCARGS ARG_MAX /* max bytes for an exec function */ |
