Bug #3099
closedSIGSEGV in early SSL_read() API call (misconfigured lighttpd.conf)
Description
Lighttpd crashes if an API call is performed relatively fast after a reboot.
If I do the same API calls a bit later, then I don't see those crashes.
I can't tell you the exact reproduction steps, but I discovered them while doing reboot tests.
This is a regression that I saw while rebasing Buildroot from 2020.02.7 to 2021.02.4.
lighttpd 1.4.55 --> 1.4.58
I also tested version 1.4.59 to be sure that https://redmine.lighttpd.net/issues/3052 isn't applicable.
Used SSL libs:
libressl 3.2.5 --> 3.2.5 (same version)
libopenssl 1.1.1g --> 1.1.1k
Strace output:
accept4(5<socket:[5859]>, {sa_family=AF_INET, sin_port=htons(56950), sin_addr=inet_addr("<ip>")}, [112->16], SOCK_CLOEXEC|SOCK_NONBLOCK) = 8<socket:[11907]>
gettimeofday({tv_sec=1630501034, tv_usec=205162}, NULL) = 0
read(8<socket:[11907]>, "<data>", 5) = 5
read(8<socket:[11907]>, "<data>"..., 183) = 183
gettimeofday({tv_sec=1630501034, tv_usec=206804}, NULL) = 0
write(8<socket:[11907]>, "<data>"..., 1277) = 1277
read(8<socket:[11907]>, 0xc76bb, 5) = -1 EAGAIN (Resource temporarily unavailable)
epoll_ctl(7<anon_inode:[eventpoll]>, EPOLL_CTL_ADD, 8<socket:[11907]>, {EPOLLIN|EPOLLERR|EPOLLHUP|EPOLLRDHUP, {u32=729704, u64=850296151155304}}) = 0
accept4(5<socket:[5859]>, 0xbed53bd8, [112], SOCK_CLOEXEC|SOCK_NONBLOCK) = -1 EAGAIN (Resource temporarily unavailable)
gettimeofday({tv_sec=1630501034, tv_usec=344363}, NULL) = 0
epoll_wait(7<anon_inode:[eventpoll]>, [{EPOLLIN, {u32=729704, u64=850296151155304}}], 1025, 1000) = 1
read(8<socket:[11907]>, "<data>", 5) = 5
read(8<socket:[11907]>, "<data>"..., 102) = 102
read(8<socket:[11907]>, "<data>", 5) = 5
read(8<socket:[11907]>, "<data>", 1) = 1
read(8<socket:[11907]>, "<data>", 5) = 5
read(8<socket:[11907]>, "<data>"..., 40) = 40
--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x10} ---
+++ killed by SIGSEGV +++
mna-240-2530066145 # client_loop: send disconnect: Broken pipe
Adding some logs learned me that it goes wrong in an SSL_read call:
https://git.lighttpd.net/lighttpd/lighttpd1.4/src/tag/lighttpd-1.4.58/src/mod_openssl.c#L2950
Let me know where I can help.
Updated by gstrauss about 3 years ago
- Has duplicate Bug #3098: SIGSEGV in early SSL_read() API call (misconfigured lighttpd.conf) added
Updated by gstrauss about 3 years ago
- Subject changed from SIGSEGV in early API call to SIGSEGV in early SSL_read() API call (misconfigured lighttpd.conf)
- Category deleted (
core) - Status changed from New to Invalid
A stack trace at the point of the crash would be useful.
Have you configured the buildroot to save core files when a program crashes?
Since you said the crash occurs in SSL_read(), you might also install the debugging symbols for the openssl library, so that you can get better information in the core file from the stack trace.
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Another alternative to test is using an alternative TLS library, such as mbedTLS with lighttpd mod_mbedtls, or wolfSSL with lighttpd mod_wolfssl.
.
All that said, based on your previous post (#3097), have you considered that there is a MUCH, MUCH higher probability that you are doing something wrong which causes the crash, than that there is a bug in a TLS library? Please see How to get support Notice that you have failed to provide critically important information such as your lighttpd.conf with lighttpd -f /etc/lighttpd/lighttpd.conf -p. A problem that occassionally comes up (which has a better warning in the upcoming lighttpd 1.4.60) is that you have misconfigured TLS in your lighttpd.conf by placing $SERVER["socket"] config in a nested condition. There are warnings in the lighttpd Configuration: File Syntax and in lighttpd TLS docs. See also #3096.
@ThomasDevoogdt:
Please do not make any further posts to the lighttpd issue tracker. Instead, please post in the lighttpd Forums
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Updated by gstrauss about 3 years ago
To be helpful to others, please post where you found the incorrect lighttpd TLS syntax. If on stackoverflow, please post the link and I'll correct the poster.
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