Short description: Work ld.so --verify crash on debuginfo files. Author(s): Fedora glibc team Origin: PATCH Bug-RHEL: #741105, #767146 Upstream status: not-needed This change is designed to work around running ld.so on a debuginfo file. This is the wrong fix for this problem and should be dropped. The correct solution is to mark debuginfo files as new types of ELF files. Index: glibc-2.22-386-g95e8397/elf/dl-load.c =================================================================== --- glibc-2.22-386-g95e8397.orig/elf/dl-load.c +++ glibc-2.22-386-g95e8397/elf/dl-load.c @@ -881,7 +881,8 @@ _dl_map_object_from_fd (const char *name /* Get file information. */ struct r_file_id id; - if (__glibc_unlikely (!_dl_get_file_id (fd, &id))) + struct stat64 st; + if (__glibc_unlikely (!_dl_get_file_id (fd, &id, &st))) { errstring = N_("cannot stat shared object"); call_lose_errno: @@ -1076,6 +1077,16 @@ _dl_map_object_from_fd (const char *name = N_("ELF load command address/offset not properly aligned"); goto call_lose; } + if (__glibc_unlikely (ph->p_offset + ph->p_filesz > st.st_size)) + { + /* If the segment requires zeroing of part of its last + page, we'll crash when accessing the unmapped page. + There's still a possibility of a race, if the shared + object is truncated between the fxstat above and the + memset below. */ + errstring = N_("ELF load command past end of file"); + goto call_lose; + } struct loadcmd *c = &loadcmds[nloadcmds++]; c->mapstart = ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize)); Index: glibc-2.22-386-g95e8397/sysdeps/generic/dl-fileid.h =================================================================== --- glibc-2.22-386-g95e8397.orig/sysdeps/generic/dl-fileid.h +++ glibc-2.22-386-g95e8397/sysdeps/generic/dl-fileid.h @@ -29,7 +29,8 @@ struct r_file_id On error, returns false, with errno set. */ static inline bool _dl_get_file_id (int fd __attribute__ ((unused)), - struct r_file_id *id __attribute__ ((unused))) + struct r_file_id *id __attribute__ ((unused)), + struct stat64_t *st __attribute__((unused))) { return true; } Index: glibc-2.22-386-g95e8397/sysdeps/posix/dl-fileid.h =================================================================== --- glibc-2.22-386-g95e8397.orig/sysdeps/posix/dl-fileid.h +++ glibc-2.22-386-g95e8397/sysdeps/posix/dl-fileid.h @@ -27,18 +27,16 @@ struct r_file_id ino64_t ino; }; -/* Sample FD to fill in *ID. Returns true on success. +/* Sample FD to fill in *ID and *ST. Returns true on success. On error, returns false, with errno set. */ static inline bool -_dl_get_file_id (int fd, struct r_file_id *id) +_dl_get_file_id (int fd, struct r_file_id *id, struct stat64 *st) { - struct stat64 st; - - if (__glibc_unlikely (__fxstat64 (_STAT_VER, fd, &st) < 0)) + if (__glibc_unlikely (__fxstat64 (_STAT_VER, fd, st) < 0)) return false; - id->dev = st.st_dev; - id->ino = st.st_ino; + id->dev = st->st_dev; + id->ino = st->st_ino; return true; }