diff options
| -rw-r--r-- | fs/binfmt_em86.c | 1 | ||||
| -rw-r--r-- | fs/binfmt_misc.c | 6 | ||||
| -rw-r--r-- | fs/binfmt_script.c | 4 | ||||
| -rw-r--r-- | fs/exec.c | 10 | ||||
| -rw-r--r-- | include/linux/binfmts.h | 2 |
5 files changed, 6 insertions, 17 deletions
diff --git a/fs/binfmt_em86.c b/fs/binfmt_em86.c index 4e6cce57d113..037a3e2b045b 100644 --- a/fs/binfmt_em86.c +++ b/fs/binfmt_em86.c @@ -42,7 +42,6 @@ static int load_em86(struct linux_binprm *bprm) return -ENOEXEC; } - bprm->recursion_depth++; /* Well, the bang-shell is implicit... */ allow_write_access(bprm->file); fput(bprm->file); bprm->file = NULL; diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index b0b70fbea06c..9be335fb8a7c 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -117,10 +117,6 @@ static int load_misc_binary(struct linux_binprm *bprm) if (!enabled) goto _ret; - retval = -ENOEXEC; - if (bprm->recursion_depth > BINPRM_MAX_RECURSION) - goto _ret; - /* to keep locking time low, we copy the interpreter string */ read_lock(&entries_lock); fmt = check_file(bprm); @@ -197,8 +193,6 @@ static int load_misc_binary(struct linux_binprm *bprm) if (retval < 0) goto _error; - bprm->recursion_depth++; - retval = search_binary_handler(bprm); if (retval < 0) goto _error; diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c index 8c954997e7f7..1610a91637e5 100644 --- a/fs/binfmt_script.c +++ b/fs/binfmt_script.c @@ -22,15 +22,13 @@ static int load_script(struct linux_binprm *bprm) char interp[BINPRM_BUF_SIZE]; int retval; - if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!') || - (bprm->recursion_depth > BINPRM_MAX_RECURSION)) + if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!')) return -ENOEXEC; /* * This section does the #! interpretation. * Sorta complicated, but hopefully it will work. -TYT */ - bprm->recursion_depth++; allow_write_access(bprm->file); fput(bprm->file); bprm->file = NULL; diff --git a/fs/exec.c b/fs/exec.c index 721a29929511..d5eb9e605ffd 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1356,6 +1356,10 @@ int search_binary_handler(struct linux_binprm *bprm) struct linux_binfmt *fmt; pid_t old_pid, old_vpid; + /* This allows 4 levels of binfmt rewrites before failing hard. */ + if (depth > 5) + return -ELOOP; + retval = security_bprm_check(bprm); if (retval) return retval; @@ -1380,12 +1384,8 @@ int search_binary_handler(struct linux_binprm *bprm) if (!try_module_get(fmt->module)) continue; read_unlock(&binfmt_lock); + bprm->recursion_depth = depth + 1; retval = fn(bprm); - /* - * Restore the depth counter to its starting value - * in this call, so we don't have to rely on every - * load_binary function to restore it on return. - */ bprm->recursion_depth = depth; if (retval >= 0) { if (depth == 0) { diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 2630c9b41a86..a4c2b565c835 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -54,8 +54,6 @@ struct linux_binprm { #define BINPRM_FLAGS_EXECFD_BIT 1 #define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT) -#define BINPRM_MAX_RECURSION 4 - /* Function parameter for binfmt->coredump */ struct coredump_params { siginfo_t *siginfo; |