| Message ID | 6D39441BF12EF246A7ABCE6654B0235320F199DC@LEMAIL01.le.imgtec.org |
|---|---|
| State | New |
| Headers | show |
> * elf/dl-load.c (dl-load-phdr.h): Include. The (...) is only for citing where you are touching. There is no function, variable, or macro called dl-load-phdr.h, so this is not right. I'm also not crazy about the name, since it sounds more generic than it really is. dl-machine-reject-phdr.h would be the most specific name. > (open_verify): Add hook for phdr check. This should be more clear about what the change is. > * sysdeps/generic/dl-load-phdr.h: New file. The new file can go into elf/ instead of sysdeps/generic/, because it is only used by code that is compiled only in the elf/ subdirectory. The sysdeps/generic/ directory is used for files that need to be found from builds in multiple subdirectories. If I'd written it, the whole log entry would look like: * elf/dl-machine-reject-phdr.h: New file. * elf/dl-load.c: #include that. (open_verify): Call elf_machine_reject_phdr_p and ignore the file if that returned false. > + if (__glibc_unlikely ( > + elf_machine_reject_phdr_p (phdr, ehdr->e_phnum, fbp->buf, fbp->len, > + fd, loader))) The indentation for this should look like: if (__glibc_unlikely (elf_machine_reject_phdr_p (phdr, ehdr->e_phnum, fbp->buf, fbp->len, fd, loader))) > +/* Machine-dependent ELF loader functions. This description is too generic for what's really here. > +#ifndef _DL_LOAD_PHDR_H > +#define _DL_LOAD_PHDR_H We always define these to 1 rather than empty. You should #include <stdbool.h> here before using bool. > +/* Return true iff ELF program headers are incompatible with the running > + host. */ > +static inline bool > +elf_machine_reject_phdr_p (const ElfW(Phdr) *phdr, uint_fast16_t phnum, > + const char *buf, size_t len, int fd, > + struct link_map *map) It would be better to swap the order of the last two arguments, so you don't have to integer types next to each other where transposing them accidentally would not produce a type error. Thanks, Roland
diff --git a/elf/dl-load.c b/elf/dl-load.c index 016a99c..c1fa923 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -41,6 +41,7 @@ #include <dl-load.h> #include <dl-map-segments.h> #include <dl-unmap-segments.h> +#include <dl-load-phdr.h> #include <endian.h> @@ -1697,6 +1698,11 @@ open_verify (const char *name, struct filebuf *fbp, struct link_map *loader, } } + if (__glibc_unlikely ( + elf_machine_reject_phdr_p (phdr, ehdr->e_phnum, fbp->buf, fbp->len, + fd, loader))) + goto close_and_out; + /* Check .note.ABI-tag if present. */ for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph) if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4) diff --git a/sysdeps/generic/dl-load-phdr.h b/sysdeps/generic/dl-load-phdr.h new file mode 100644 index 0000000..4e98f92 --- /dev/null +++ b/sysdeps/generic/dl-load-phdr.h @@ -0,0 +1,32 @@ +/* Machine-dependent ELF loader functions. + Copyright (C) 2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _DL_LOAD_PHDR_H +#define _DL_LOAD_PHDR_H + +/* Return true iff ELF program headers are incompatible with the running + host. */ +static inline bool +elf_machine_reject_phdr_p (const ElfW(Phdr) *phdr, uint_fast16_t phnum, + const char *buf, size_t len, int fd, + struct link_map *map) +{ + return false; +} + +#endif /* dl-load-phdr.h */