diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | elf/Makefile | 8 | ||||
| -rw-r--r-- | elf/dl-load.c | 21 | ||||
| -rw-r--r-- | elf/tst-big-note-lib.S | 26 | ||||
| -rw-r--r-- | elf/tst-big-note.c | 26 |
5 files changed, 85 insertions, 4 deletions
@@ -1,3 +1,11 @@ +2018-05-05 Paul Pluzhnikov <ppluzhnikov@google.com> + + [BZ #20419] + * elf/dl-load.c (open_verify): Fix stack overflow. + * elf/Makefile (tst-big-note): New test. + * elf/tst-big-note-lib.S: New. + * elf/tst-big-note.c: New. + 2018-05-04 Joseph Myers <joseph@codesourcery.com> * scripts/abilist.awk: Ignore absolute symbols. diff --git a/elf/Makefile b/elf/Makefile index e658928305..2dcd2b88e0 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -186,7 +186,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-tlsalign tst-tlsalign-extern tst-nodelete-opened \ tst-nodelete2 tst-audit11 tst-audit12 tst-dlsym-error tst-noload \ tst-latepthread tst-tls-manydynamic tst-nodelete-dlclose \ - tst-debug1 tst-main1 tst-absolute-sym + tst-debug1 tst-main1 tst-absolute-sym tst-big-note # reldep9 tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ @@ -272,7 +272,9 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ tst-audit12mod1 tst-audit12mod2 tst-audit12mod3 tst-auditmod12 \ tst-latepthreadmod $(tst-tls-many-dynamic-modules) \ tst-nodelete-dlclose-dso tst-nodelete-dlclose-plugin \ - tst-main1mod tst-libc_dlvsym-dso tst-absolute-sym-lib + tst-main1mod tst-libc_dlvsym-dso tst-absolute-sym-lib \ + tst-big-note-lib + ifeq (yes,$(have-mtls-dialect-gnu2)) tests += tst-gnu2-tls1 modules-names += tst-gnu2-tls1mod @@ -1450,3 +1452,5 @@ $(objpfx)tst-libc_dlvsym-static: $(common-objpfx)dlfcn/libdl.a tst-libc_dlvsym-static-ENV = \ LD_LIBRARY_PATH=$(objpfx):$(common-objpfx):$(common-objpfx)dlfcn $(objpfx)tst-libc_dlvsym-static.out: $(objpfx)tst-libc_dlvsym-dso.so + +$(objpfx)tst-big-note: $(objpfx)tst-big-note-lib.so diff --git a/elf/dl-load.c b/elf/dl-load.c index a5e3a25462..431236920f 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1462,6 +1462,7 @@ open_verify (const char *name, int fd, ElfW(Ehdr) *ehdr; ElfW(Phdr) *phdr, *ph; ElfW(Word) *abi_note; + ElfW(Word) *abi_note_malloced = NULL; unsigned int osversion; size_t maplength; @@ -1633,10 +1634,25 @@ open_verify (const char *name, int fd, abi_note = (void *) (fbp->buf + ph->p_offset); else { - abi_note = alloca (size); + /* Note: __libc_use_alloca is not usable here, because + thread info may not have been set up yet. */ + if (size < __MAX_ALLOCA_CUTOFF) + abi_note = alloca (size); + else + { + /* There could be multiple PT_NOTEs. */ + abi_note_malloced = realloc (abi_note_malloced, size); + if (abi_note_malloced == NULL) + goto read_error; + + abi_note = abi_note_malloced; + } __lseek (fd, ph->p_offset, SEEK_SET); if (__libc_read (fd, (void *) abi_note, size) != size) - goto read_error; + { + free (abi_note_malloced); + goto read_error; + } } while (memcmp (abi_note, &expected_note, sizeof (expected_note))) @@ -1671,6 +1687,7 @@ open_verify (const char *name, int fd, break; } + free (abi_note_malloced); } return fd; diff --git a/elf/tst-big-note-lib.S b/elf/tst-big-note-lib.S new file mode 100644 index 0000000000..6b514a03cc --- /dev/null +++ b/elf/tst-big-note-lib.S @@ -0,0 +1,26 @@ +/* Bug 20419: test for stack overflow in elf/dl-load.c open_verify() + Copyright (C) 2018 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/>. */ + +/* This creates a .so with 8MiB PT_NOTE segment. + On a typical Linux system with 8MiB "ulimit -s", that was enough + to trigger stack overflow in open_verify. */ + +.pushsection .note.big,"a" +.balign 4 +.fill 8*1024*1024, 1, 0 +.popsection diff --git a/elf/tst-big-note.c b/elf/tst-big-note.c new file mode 100644 index 0000000000..fcd2b0ed82 --- /dev/null +++ b/elf/tst-big-note.c @@ -0,0 +1,26 @@ +/* Bug 20419: test for stack overflow in elf/dl-load.c open_verify() + Copyright (C) 2018 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/>. */ + +/* This file must be run from within a directory called "elf". */ + +int main (int argc, char *argv[]) +{ + /* Nothing to do here: merely linking against tst-big-note-lib.so triggers + the bug. */ + return 0; +} |