Messages in this thread | | | From | Namhyung Kim <> | Date | Tue, 22 Jun 2021 12:46:38 -0700 | Subject | Re: [PATCH] perf top: fix overflow in elf_sec__is_text |
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Hi Riccardo,
On Mon, Jun 21, 2021 at 3:22 PM Riccardo Mancini <rickyman7@gmail.com> wrote: > > ASan reports a heap-buffer-overflow in elf_sec__is_text when using perf-top. > The bug is caused by the fact that secstrs is built from runtime_ss, while > shdr is built from syms_ss if shdr.sh_type != SHT_NOBITS. Therefore, they > point to two different ELF files. > > This patch renames secstrs to secstrs_run and adds secstrs_sym, so that > the correct secstrs is chosen depending on shdr.sh_type. > > $ ASAN_OPTIONS=abort_on_error=1:disable_coredump=0:unmap_shadow_on_exit=1 ./perf top > ================================================================= > ==363148==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61300009add6 at pc 0x00000049875c bp 0x7f4f56446440 sp 0x7f4f56445bf0 > READ of size 1 at 0x61300009add6 thread T6 > #0 0x49875b in StrstrCheck(void*, char*, char const*, char const*) (/home/user/linux/tools/perf/perf+0x49875b) > #1 0x4d13a2 in strstr (/home/user/linux/tools/perf/perf+0x4d13a2) > #2 0xacae36 in elf_sec__is_text /home/user/linux/tools/perf/util/symbol-elf.c:176:9 > #3 0xac3ec9 in elf_sec__filter /home/user/linux/tools/perf/util/symbol-elf.c:187:9 > #4 0xac2c3d in dso__load_sym /home/user/linux/tools/perf/util/symbol-elf.c:1254:20 > #5 0x883981 in dso__load /home/user/linux/tools/perf/util/symbol.c:1897:9 > #6 0x8e6248 in map__load /home/user/linux/tools/perf/util/map.c:332:7 > #7 0x8e66e5 in map__find_symbol /home/user/linux/tools/perf/util/map.c:366:6 > #8 0x7f8278 in machine__resolve /home/user/linux/tools/perf/util/event.c:707:13 > #9 0x5f3d1a in perf_event__process_sample /home/user/linux/tools/perf/builtin-top.c:773:6 > #10 0x5f30e4 in deliver_event /home/user/linux/tools/perf/builtin-top.c:1197:3 > #11 0x908a72 in do_flush /home/user/linux/tools/perf/util/ordered-events.c:244:9 > #12 0x905fae in __ordered_events__flush /home/user/linux/tools/perf/util/ordered-events.c:323:8 > #13 0x9058db in ordered_events__flush /home/user/linux/tools/perf/util/ordered-events.c:341:9 > #14 0x5f19b1 in process_thread /home/user/linux/tools/perf/builtin-top.c:1109:7 > #15 0x7f4f6a21a298 in start_thread /usr/src/debug/glibc-2.33-16.fc34.x86_64/nptl/pthread_create.c:481:8 > #16 0x7f4f697d0352 in clone ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 > > 0x61300009add6 is located 10 bytes to the right of 332-byte region [0x61300009ac80,0x61300009adcc) > allocated by thread T6 here: > #0 0x4f3f7f in malloc (/home/user/linux/tools/perf/perf+0x4f3f7f) > #1 0x7f4f6a0a88d9 (/lib64/libelf.so.1+0xa8d9) > > Thread T6 created by T0 here: > #0 0x464856 in pthread_create (/home/user/linux/tools/perf/perf+0x464856) > #1 0x5f06e0 in __cmd_top /home/user/linux/tools/perf/builtin-top.c:1309:6 > #2 0x5ef19f in cmd_top /home/user/linux/tools/perf/builtin-top.c:1762:11 > #3 0x7b28c0 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 > #4 0x7b119f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 > #5 0x7b2423 in run_argv /home/user/linux/tools/perf/perf.c:409:2 > #6 0x7b0c19 in main /home/user/linux/tools/perf/perf.c:539:3 > #7 0x7f4f696f7b74 in __libc_start_main /usr/src/debug/glibc-2.33-16.fc34.x86_64/csu/../csu/libc-start.c:332:16 > > SUMMARY: AddressSanitizer: heap-buffer-overflow (/home/user/linux/tools/perf/perf+0x49875b) in StrstrCheck(void*, char*, char const*, char const*) > Shadow bytes around the buggy address: > 0x0c268000b560: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa > 0x0c268000b570: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa > 0x0c268000b580: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa > 0x0c268000b590: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 0x0c268000b5a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > =>0x0c268000b5b0: 00 00 00 00 00 00 00 00 00 04[fa]fa fa fa fa fa > 0x0c268000b5c0: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 > 0x0c268000b5d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 0x0c268000b5e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 0x0c268000b5f0: 07 fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa > 0x0c268000b600: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd > Shadow byte legend (one shadow byte represents 8 application bytes): > Addressable: 00 > Partially addressable: 01 02 03 04 05 06 07 > Heap left redzone: fa > Freed heap region: fd > Stack left redzone: f1 > Stack mid redzone: f2 > Stack right redzone: f3 > Stack after return: f5 > Stack use after scope: f8 > Global redzone: f9 > Global init order: f6 > Poisoned by user: f7 > Container overflow: fc > Array cookie: ac > Intra object redzone: bb > ASan internal: fe > Left alloca redzone: ca > Right alloca redzone: cb > Shadow gap: cc > ==363148==ABORTING > > Signed-off-by: Riccardo Mancini <rickyman7@gmail.com> > Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Thanks, Namhyung
> --- > tools/perf/util/symbol-elf.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c > index 4c56aa837434..7a6e38bf87b0 100644 > --- a/tools/perf/util/symbol-elf.c > +++ b/tools/perf/util/symbol-elf.c > @@ -1081,7 +1081,7 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, > struct maps *kmaps = kmap ? map__kmaps(map) : NULL; > struct map *curr_map = map; > struct dso *curr_dso = dso; > - Elf_Data *symstrs, *secstrs; > + Elf_Data *symstrs, *secstrs, *secstrs_run, *secstrs_sym; > uint32_t nr_syms; > int err = -1; > uint32_t idx; > @@ -1150,8 +1150,16 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, > if (sec_strndx == NULL) > goto out_elf_end; > > - secstrs = elf_getdata(sec_strndx, NULL); > - if (secstrs == NULL) > + secstrs_run = elf_getdata(sec_strndx, NULL); > + if (secstrs_run == NULL) > + goto out_elf_end; > + > + sec_strndx = elf_getscn(elf, ehdr.e_shstrndx); > + if (sec_strndx == NULL) > + goto out_elf_end; > + > + secstrs_sym = elf_getdata(sec_strndx, NULL); > + if (secstrs_sym == NULL) > goto out_elf_end; > > nr_syms = shdr.sh_size / shdr.sh_entsize; > @@ -1237,6 +1245,8 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, > > gelf_getshdr(sec, &shdr); > > + secstrs = secstrs_sym; > + > /* > * We have to fallback to runtime when syms' section header has > * NOBITS set. NOBITS results in file offset (sh_offset) not > @@ -1249,6 +1259,7 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, > goto out_elf_end; > > gelf_getshdr(sec, &shdr); > + secstrs = secstrs_run; > } > > if (is_label && !elf_sec__filter(&shdr, secstrs)) > -- > 2.23.0 >
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