Reply-To: Hmm... That's weird. I can reproduce it on 3 independant systems with versions 2.16.2 up, although it does not work with version 2.11.0. Anyway, I figured out how to reproduce this bug. It is caused when a submodule is added and then the directory it resides in is moved or deleted without commiting. For example: git init git submodule add https://github.com/git/git git mv git git.BAK git submodule status #this command segfaults cheers Jeremy In-Reply-To: <a7ad9dbf-1b0f-efc6-3a17-51cf25381ce5@xxxxxx> On Sat, Mar 24, 2018 at 09:42:57PM +0100, René Scharfe wrote: > Am 24.03.2018 um 18:42 schrieb Jeremy Feusi: > > Hi, > > While bootstrapping a gnu repository I noticed that git segfaulted when > > called as "git submodule status". After compiling git with address > > sanitizer and minimizing the directory I finally narrowed it down to the > > files which I have attached as a tar archive. Here is a detailed backtrace: > > > > AddressSanitizer:DEADLYSIGNAL > > ================================================================= > > ==63400==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x000000c27a93 bp 0x7ffdcb4eec10 sp 0x7ffdcb4eeb80 T0) > > ==63400==The signal is caused by a READ memory access. > > ==63400==Hint: address points to the zero page. > > #0 0xc27a92 in refs_read_raw_ref /home/jfe/git/refs.c:1451:20 > > #1 0xc174a6 in refs_resolve_ref_unsafe /home/jfe/git/refs.c:1493:7 > > #2 0xc1826a in refs_read_ref_full /home/jfe/git/refs.c:224:6 > > #3 0xc26d53 in refs_head_ref /home/jfe/git/refs.c:1314:7 > > #4 0x8071e6 in status_submodule /home/jfe/git/builtin/submodule--helper.c:658:7 > > #5 0x806a89 in status_submodule_cb /home/jfe/git/builtin/submodule--helper.c:699:2 > > #6 0x80523e in for_each_listed_submodule /home/jfe/git/builtin/submodule--helper.c:438:3 > > #7 0x7f7e9a in module_status /home/jfe/git/builtin/submodule--helper.c:732:2 > > #8 0x7efd69 in cmd_submodule__helper /home/jfe/git/builtin/submodule--helper.c:1859:11 > > #9 0x51e024 in run_builtin /home/jfe/git/git.c:346:11 > > #10 0x5192c2 in handle_builtin /home/jfe/git/git.c:554:8 > > #11 0x51d0f0 in run_argv /home/jfe/git/git.c:606:4 > > #12 0x518600 in cmd_main /home/jfe/git/git.c:683:19 > > #13 0x8501d6 in main /home/jfe/git/common-main.c:43:9 > > #14 0x7f49fdaf2f29 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x20f29) > > #15 0x41f4b9 in _start (/home/jfe/git/inst/libexec/git-core/git+0x41f4b9) > > > > AddressSanitizer can not provide additional info. > > SUMMARY: AddressSanitizer: SEGV /home/jfe/git/refs.c:1451:20 in refs_read_raw_ref > > ==63400==ABORTING > > > > As mentioned above, this bug is triggered by issuing the command > > "git submodule status" while in the attached directory. > > > > This bug was confirmed on Debian with version 2.16.1 and > > 2.17.0.rc1.35.g90bbd502d as well as on Arch Linux with version 2.16.2 > > where further output is given by git: > > > > /usr/lib/git-core/git-submodule: line 979: 8119 Segmentation fault (core dumped) git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper status ${GIT_QUIET:+--quiet} ${cached:+--cached} ${recursive:+--recursive} "$@" > > > > You may have minimized too much. With the patch below I get: > > fatal: no ref store in submodule 'gnulib' > > I guess you'll get a different one in your original repo. > > The patch seems like a good idea in any case, though. > > -- >8 -- > Subject: [PATCH] submodule: check for NULL return of get_submodule_ref_store() > > refs_head_ref() requires a valid ref_store pointer to be given as its > first argument. get_submodule_ref_store() can return NULL. Exit and > report the failure to find a ref store in that case instead of > segfaulting. > > Reported-by: Jeremy Feusi <jeremy@xxxxxxxx> > Signed-off-by: Rene Scharfe <l.s.r@xxxxxx> > --- > builtin/submodule--helper.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c > index ee020d4749..0f74e81005 100644 > --- a/builtin/submodule--helper.c > +++ b/builtin/submodule--helper.c > @@ -654,9 +654,11 @@ static void status_submodule(const char *path, const struct object_id *ce_oid, > displaypath); > } else if (!(flags & OPT_CACHED)) { > struct object_id oid; > + struct ref_store *refs = get_submodule_ref_store(path); > > - if (refs_head_ref(get_submodule_ref_store(path), > - handle_submodule_head_ref, &oid)) > + if (!refs) > + die(_("no ref store in submodule '%s'"), path); > + if (refs_head_ref(refs, handle_submodule_head_ref, &oid)) > die(_("could not resolve HEAD ref inside the " > "submodule '%s'"), path); > > -- > 2.16.3
