8 a.m.
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
Bug ID: 1886816
Summary: [abrt] sssd-common: sss_mmap_cache_pw_store():
sssd_nss killed by SIGBUS
Product: Fedora
Version: 33
Hardware: x86_64
Status: NEW
Whiteboard: abrt_hash:cd13c552f85949e67c1f8b9066dc4393eee0ce85;VAR
IANT_ID=workstation;
Component: sssd
Assignee: sssd-maintainers(a)lists.fedoraproject.org
Reporter: kparal(a)redhat.com
QA Contact: extras-qa(a)fedoraproject.org
CC: abokovoy(a)redhat.com, atikhono(a)redhat.com,
jhrozek(a)redhat.com, lslebodn(a)redhat.com,
mzidek(a)redhat.com, pbrezina(a)redhat.com,
rharwood(a)redhat.com, sbose(a)redhat.com,
ssorce(a)redhat.com,
sssd-maintainers(a)lists.fedoraproject.org
Target Milestone: ---
Classification: Fedora
Version-Release number of selected component:
sssd-common-2.3.1-4.fc33
Additional info:
reporter: libreport-2.14.0
backtrace_rating: 4
cgroup: 0::/system.slice/sssd.service
cmdline: /usr/libexec/sssd/sssd_nss --uid 0 --gid 0 --logger=files
crash_function: sss_mmap_cache_pw_store
executable: /usr/libexec/sssd/sssd_nss
journald_cursor:
s=b2e7c0583c004ae8bd317a4440255076;i=2ee4a7;b=7c261537394f4d169971a59cd1761dfe;m=55626889;t=5b13c2149d0cf;x=8fed0b78d48ecd6c
kernel: 5.8.14-300.fc33.x86_64
rootdir: /
runlevel: N 5
type: CCpp
uid: 0
Truncated backtrace:
Thread no. 1 (10 frames)
#0 sss_mmap_cache_pw_store at src/responder/nss/nsssrv_mmap_cache.c:769
#1 nss_protocol_fill_pwent at src/responder/nss/nss_protocol_pwent.c:308
#2 nss_protocol_reply at src/responder/nss/nss_protocol.c:91
#3 nss_getby_done at src/responder/nss/nss_cmd.c:626
#4 tevent_common_invoke_immediate_handler at ../../tevent_immediate.c:166
#5 tevent_common_loop_immediate at ../../tevent_immediate.c:203
#6 epoll_event_loop_once at ../../tevent_epoll.c:917
#7 std_event_loop_once at ../../tevent_standard.c:110
#8 _tevent_loop_once at ../../tevent.c:772
#9 tevent_common_loop_wait at ../../tevent.c:895
--
You are receiving this mail because:
You are on the CC list for the bug.
You are the assignee for the bug.
9:04 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
Alexey Tikhonov <atikhono(a)redhat.com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Flags| |needinfo?(kparal(a)redhat.com
| |)
--- Comment #13 from Alexey Tikhonov <atikhono(a)redhat.com> ---
Hi Kamil,
do you have a coredump?
--
You are receiving this mail because:
You are on the CC list for the bug.
You are the assignee for the bug.
9:11 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
--- Comment #14 from Alexey Tikhonov <atikhono(a)redhat.com> ---
Program terminated with signal SIGBUS, Bus error.
#0 0x000055b728aceb15 in sss_mmap_cache_pw_store
(_mcc=_mcc@entry=0x55b72a00dd28, name=0x55b72a030380,
pw=pw@entry=0x7fff947313c0, uid=uid@entry=173, gid=gid@entry=173,
gecos=gecos@entry=0x7fff947313d0, homedir=0x7fff947313e0, shell=0x7fff947313f0)
at src/responder/nss/nsssrv_mmap_cache.c:769
This ^^ is `MC_RAISE_BARRIER(rec);`:
```
#define MC_RAISE_BARRIER(m) do { \
m->b2 = MC_NEXT_BARRIER(m->b1); \
__sync_synchronize(); \
} while (0)
```
In "open_fds" there is:
```
17:/var/lib/sss/mc/passwd (deleted)
pos: 0
flags: 02100000
mnt_id: 65
18:/var/lib/sss/mc/passwd
pos: 0
flags: 0100002
mnt_id: 65
lock: 1: POSIX ADVISORY WRITE 710 00:20:429251 0 0
```
-- seems SIGBUS was triggered by attempt to access memory mmap-ed to deleted
file.
Is there any chance this file ("/var/lib/sss/mc/passwd") was deleted by some
outer process?
--
You are receiving this mail because:
You are on the CC list for the bug.
You are the assignee for the bug.
9:12 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
Kamil Páral <kparal(a)redhat.com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Flags|needinfo?(kparal(a)redhat.com |
|) |
--- Comment #15 from Kamil Páral <kparal(a)redhat.com> ---
Created attachment 1720291
--> https://bugzilla.redhat.com/attachment.cgi?id=1720291&action=edit
coredump
Yes, here it is. I have no idea how it happened and how to reproduce that.
--
You are receiving this mail because:
You are on the CC list for the bug.
You are the assignee for the bug.
9:14 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
--- Comment #16 from Kamil Páral <kparal(a)redhat.com> ---
Is there any chance this file ("/var/lib/sss/mc/passwd")
was deleted by some outer process?
I don't know, this is a fairly fresh F33 VM, and I wasn't doing anything
particularly interesting, just playing with abrt. The file is currently there:
$ ll /var/lib/sss/mc/passwd
-rw-rw-r--. 1 root root 9253600 Oct 9 16:12 /var/lib/sss/mc/passwd
--
You are receiving this mail because:
You are on the CC list for the bug.
You are the assignee for the bug.
4:39 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
Pavel Březina <pbrezina(a)redhat.com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|sssd-maintainers(a)lists.fedo |atikhono(a)redhat.com
|raproject.org |
--
You are receiving this mail because:
You are on the CC list for the bug.
You are the assignee for the bug.
8:29 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
Alexey Tikhonov <atikhono(a)redhat.com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|atikhono(a)redhat.com |sbose(a)redhat.com
--
You are receiving this mail because:
You are on the CC list for the bug.
2:42 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
Alexey Tikhonov <atikhono(a)redhat.com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |kheine7(a)gmail.com
--- Comment #17 from Alexey Tikhonov <atikhono(a)redhat.com> ---
*** Bug 1974235 has been marked as a duplicate of this bug. ***
--
You are receiving this mail because:
You are on the CC list for the bug.
8:44 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
--- Comment #18 from Ben Cotton <bcotton(a)redhat.com> ---
This message is a reminder that Fedora 33 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora 33 on 2021-11-30.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with
a
Fedora 'version' of '33'.
Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version'
to a later Fedora version.
Thank you for reporting this issue and we are sorry that we were not
able to fix it before Fedora 33 is end of life. If you would still like
to see this bug fixed and are able to reproduce it against a later version
of Fedora, you are encouraged change the 'version' to a later Fedora
version prior this bug is closed as described in the policy above.
Although we aim to fix as many bugs as possible during every release's
lifetime, sometimes those efforts are overtaken by events. Often a
more recent Fedora release includes newer upstream software that fixes
bugs or makes them obsolete.
--
You are receiving this mail because:
You are on the CC list for the bug.
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
9:14 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
--- Comment #19 from Ben Cotton <bcotton(a)redhat.com> ---
This message is a reminder that Fedora 33 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora 33 on 2021-11-30.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with
a
Fedora 'version' of '33'.
Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version'
to a later Fedora version.
Thank you for reporting this issue and we are sorry that we were not
able to fix it before Fedora 33 is end of life. If you would still like
to see this bug fixed and are able to reproduce it against a later version
of Fedora, you are encouraged change the 'version' to a later Fedora
version prior this bug is closed as described in the policy above.
Although we aim to fix as many bugs as possible during every release's
lifetime, sometimes those efforts are overtaken by events. Often a
more recent Fedora release includes newer upstream software that fixes
bugs or makes them obsolete.
--
You are receiving this mail because:
You are on the CC list for the bug.
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
10:12 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
--- Comment #20 from Ben Cotton <bcotton(a)redhat.com> ---
This message is a reminder that Fedora 33 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora 33 on 2021-11-30.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with
a
Fedora 'version' of '33'.
Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version'
to a later Fedora version.
Thank you for reporting this issue and we are sorry that we were not
able to fix it before Fedora 33 is end of life. If you would still like
to see this bug fixed and are able to reproduce it against a later version
of Fedora, you are encouraged change the 'version' to a later Fedora
version prior this bug is closed as described in the policy above.
Although we aim to fix as many bugs as possible during every release's
lifetime, sometimes those efforts are overtaken by events. Often a
more recent Fedora release includes newer upstream software that fixes
bugs or makes them obsolete.
--
You are receiving this mail because:
You are on the CC list for the bug.
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
11:34 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
--- Comment #21 from Sumit Bose <sbose(a)redhat.com> ---
Hi,
I run couple of tests and was able to reproduce similar crashes with SIGBUS
only on files which were shortened with e.g. the truncate command. I'm not sure
if it is worth to try to protect the memory mapped files against this. I'm also
not sure how. Calling fstat() before every memory access will slow things down
considerably. Maybe sssd_nss can set an inotify watch to detect such a change
but there would still be a chance the the truncation happens while sssd_nss is
working in the files before handling inotify.
The most promising protection I found is F_SEAL_SHRINK, see man fcntl for
details, but this requires an anonymous file in tmpfs, see man memfd_create for
details.
bye,
Sumit
--
You are receiving this mail because:
You are on the CC list for the bug.
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
1:31 p.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
--- Comment #22 from Simo Sorce <ssorce(a)redhat.com> ---
The only good way to handle this is to change how we open the memory mapped
files.
Instead of opening them directly from the client, we need to introduce a new
command call over the pipe that will ask the parent to open them for us, and
then pass the fd over the socket to the client.
This method has a few advantages:
- clients will not be allowed to directly open mmapped files which means the
only thing to bind mount over (for stuff like container access) is the sockets.
- the server can simply create new files when needed and just *mark* the old
files as obsoleted before simply renaming them or even unlink() them on the
spot.
- the server can move the cache files at will. for Example it can decide to
create them on tmpfs for speed on machines where populating the cache at every
reboot is ok, while keeping them on long lived storage for machines (like
laptops) that are frequently rebooting in disconnected mode and need to
preserve the caches.
Once this is done, the only case of encountering a truncated() file in the
client is generally a server bug. The server should never change the size of
the cache files, it should always mark and rename/unlink an old cache and
create a new one instead.
--
You are receiving this mail because:
You are on the CC list for the bug.
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
10:08 a.m.
New subject: [Bug 1886816] [abrt] sssd-common: sss_mmap_cache_pw_store(): sssd_nss killed by SIGBUS
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
Ben Cotton <bcotton(a)redhat.com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |EOL
Status|NEW |CLOSED
Last Closed| |2021-11-30 16:08:52
--- Comment #23 from Ben Cotton <bcotton(a)redhat.com> ---
Fedora 33 changed to end-of-life (EOL) status on 2021-11-30. Fedora 33 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.
If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
are unable to reopen this bug, please file a new report against the
current release. If you experience problems, please add a comment to this
bug.
Thank you for reporting this bug and we are sorry it could not be fixed.
--
You are receiving this mail because:
You are on the CC list for the bug.
https://bugzilla.redhat.com/show_bug.cgi?id=1886816
871
days inactive
1288
days old
sssd-maintainers@lists.fedoraproject.org
13 comments
1 participants
participants (1)
-
bugzilla＠redhat.com