Date: Wed, 28 Oct 2015 11:29:54 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r290097 - stable/10/sys/kern Message-ID: <201510281129.t9SBTs9v031213@repo.freebsd.org>
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Author: kib Date: Wed Oct 28 11:29:54 2015 New Revision: 290097 URL: https://svnweb.freebsd.org/changeset/base/290097 Log: MFC r289322: Allow PT_INTERP and PT_NOTES segments to be located anywhere in the executable image. Modified: stable/10/sys/kern/imgact_elf.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/kern/imgact_elf.c ============================================================================== --- stable/10/sys/kern/imgact_elf.c Wed Oct 28 11:28:46 2015 (r290096) +++ stable/10/sys/kern/imgact_elf.c Wed Oct 28 11:29:54 2015 (r290097) @@ -715,21 +715,22 @@ fail: static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp) { - const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; + struct thread *td; + const Elf_Ehdr *hdr; const Elf_Phdr *phdr; Elf_Auxargs *elf_auxargs; struct vmspace *vmspace; - vm_prot_t prot; - u_long text_size = 0, data_size = 0, total_size = 0; - u_long text_addr = 0, data_addr = 0; - u_long seg_size, seg_addr; - u_long addr, baddr, et_dyn_addr, entry = 0, proghdr = 0; - int32_t osrel = 0; - int error = 0, i, n, interp_name_len = 0; - const char *err_str = NULL, *interp = NULL, *newinterp = NULL; + const char *err_str, *newinterp; + char *interp, *interp_buf, *path; Elf_Brandinfo *brand_info; - char *path; struct sysentvec *sv; + vm_prot_t prot; + u_long text_size, data_size, total_size, text_addr, data_addr; + u_long seg_size, seg_addr, addr, baddr, et_dyn_addr, entry, proghdr; + int32_t osrel; + int error, i, n, interp_name_len, have_interp; + + hdr = (const Elf_Ehdr *)imgp->image_header; /* * Do we have a valid ELF header ? @@ -757,8 +758,17 @@ __CONCAT(exec_, __elfN(imgact))(struct i uprintf("Unaligned program headers\n"); return (ENOEXEC); } - n = 0; + + n = error = 0; baddr = 0; + osrel = 0; + text_size = data_size = total_size = text_addr = data_addr = 0; + entry = proghdr = 0; + interp_name_len = 0; + err_str = newinterp = NULL; + interp = interp_buf = NULL; + td = curthread; + for (i = 0; i < hdr->e_phnum; i++) { switch (phdr[i].p_type) { case PT_LOAD: @@ -768,14 +778,32 @@ __CONCAT(exec_, __elfN(imgact))(struct i break; case PT_INTERP: /* Path to interpreter */ - if (phdr[i].p_filesz > MAXPATHLEN || - phdr[i].p_offset > PAGE_SIZE || - phdr[i].p_filesz > PAGE_SIZE - phdr[i].p_offset) { + if (phdr[i].p_filesz > MAXPATHLEN) { uprintf("Invalid PT_INTERP\n"); - return (ENOEXEC); + error = ENOEXEC; + goto ret; } - interp = imgp->image_header + phdr[i].p_offset; interp_name_len = phdr[i].p_filesz; + if (phdr[i].p_offset > PAGE_SIZE || + interp_name_len > PAGE_SIZE - phdr[i].p_offset) { + VOP_UNLOCK(imgp->vp, 0); + interp_buf = malloc(interp_name_len + 1, M_TEMP, + M_WAITOK); + vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); + error = vn_rdwr(UIO_READ, imgp->vp, interp_buf, + interp_name_len, phdr[i].p_offset, + UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, + NOCRED, NULL, td); + if (error != 0) { + uprintf("i/o error PT_INTERP\n"); + goto ret; + } + interp_buf[interp_name_len] = '\0'; + interp = interp_buf; + } else { + interp = __DECONST(char *, imgp->image_header) + + phdr[i].p_offset; + } break; case PT_GNU_STACK: if (__elfN(nxstack)) @@ -791,12 +819,14 @@ __CONCAT(exec_, __elfN(imgact))(struct i if (brand_info == NULL) { uprintf("ELF binary type \"%u\" not known.\n", hdr->e_ident[EI_OSABI]); - return (ENOEXEC); + error = ENOEXEC; + goto ret; } if (hdr->e_type == ET_DYN) { if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0) { uprintf("Cannot execute shared object\n"); - return (ENOEXEC); + error = ENOEXEC; + goto ret; } /* * Honour the base load address from the dso if it is @@ -829,8 +859,8 @@ __CONCAT(exec_, __elfN(imgact))(struct i imgp->proc->p_sysent = sv; vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); - if (error) - return (error); + if (error != 0) + goto ret; for (i = 0; i < hdr->e_phnum; i++) { switch (phdr[i].p_type) { @@ -843,7 +873,7 @@ __CONCAT(exec_, __elfN(imgact))(struct i phdr[i].p_memsz, phdr[i].p_filesz, prot, sv->sv_pagesize); if (error != 0) - return (error); + goto ret; /* * If this segment contains the program headers, @@ -915,7 +945,8 @@ __CONCAT(exec_, __elfN(imgact))(struct i if (err_str != NULL) { PROC_UNLOCK(imgp->proc); uprintf("%s\n", err_str); - return (ENOMEM); + error = ENOMEM; + goto ret; } vmspace = imgp->proc->p_vmspace; @@ -937,7 +968,7 @@ __CONCAT(exec_, __elfN(imgact))(struct i imgp->entry_addr = entry; if (interp != NULL) { - int have_interp = FALSE; + have_interp = FALSE; VOP_UNLOCK(imgp->vp, 0); if (brand_info->emul_path != NULL && brand_info->emul_path[0] != '\0') { @@ -963,7 +994,7 @@ __CONCAT(exec_, __elfN(imgact))(struct i vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); if (error != 0) { uprintf("ELF interpreter %s not found\n", interp); - return (error); + goto ret; } } else addr = et_dyn_addr; @@ -986,6 +1017,8 @@ __CONCAT(exec_, __elfN(imgact))(struct i imgp->reloc_base = addr; imgp->proc->p_osrel = osrel; + ret: + free(interp_buf, M_TEMP); return (error); } @@ -2037,19 +2070,42 @@ __elfN(parse_notes)(struct image_params { const Elf_Note *note, *note0, *note_end; const char *note_name; - int i; + char *buf; + int i, error; + boolean_t res; - if (pnote == NULL || pnote->p_offset > PAGE_SIZE || - pnote->p_filesz > PAGE_SIZE - pnote->p_offset) + /* We need some limit, might as well use PAGE_SIZE. */ + if (pnote == NULL || pnote->p_filesz > PAGE_SIZE) return (FALSE); - - note = note0 = (const Elf_Note *)(imgp->image_header + pnote->p_offset); - note_end = (const Elf_Note *)(imgp->image_header + - pnote->p_offset + pnote->p_filesz); + ASSERT_VOP_LOCKED(imgp->vp, "parse_notes"); + if (pnote->p_offset > PAGE_SIZE || + pnote->p_filesz > PAGE_SIZE - pnote->p_offset) { + VOP_UNLOCK(imgp->vp, 0); + buf = malloc(pnote->p_filesz, M_TEMP, M_WAITOK); + vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY); + error = vn_rdwr(UIO_READ, imgp->vp, buf, pnote->p_filesz, + pnote->p_offset, UIO_SYSSPACE, IO_NODELOCKED, + curthread->td_ucred, NOCRED, NULL, curthread); + if (error != 0) { + uprintf("i/o error PT_NOTE\n"); + res = FALSE; + goto ret; + } + note = note0 = (const Elf_Note *)buf; + note_end = (const Elf_Note *)(buf + pnote->p_filesz); + } else { + note = note0 = (const Elf_Note *)(imgp->image_header + + pnote->p_offset); + note_end = (const Elf_Note *)(imgp->image_header + + pnote->p_offset + pnote->p_filesz); + buf = NULL; + } for (i = 0; i < 100 && note >= note0 && note < note_end; i++) { if (!aligned(note, Elf32_Addr) || (const char *)note_end - - (const char *)note < sizeof(Elf_Note)) - return (FALSE); + (const char *)note < sizeof(Elf_Note)) { + res = FALSE; + goto ret; + } if (note->n_namesz != checknote->hdr.n_namesz || note->n_descsz != checknote->hdr.n_descsz || note->n_type != checknote->hdr.n_type) @@ -2065,17 +2121,21 @@ __elfN(parse_notes)(struct image_params * from the ELF OSABI-note if necessary. */ if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 && - checknote->trans_osrel != NULL) - return (checknote->trans_osrel(note, osrel)); - return (TRUE); - + checknote->trans_osrel != NULL) { + res = checknote->trans_osrel(note, osrel); + goto ret; + } + res = TRUE; + goto ret; nextnote: note = (const Elf_Note *)((const char *)(note + 1) + roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE) + roundup2(note->n_descsz, ELF_NOTE_ROUNDSIZE)); } - - return (FALSE); + res = FALSE; +ret: + free(buf, M_TEMP); + return (res); } /*
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