https://gitlab.synchro.net/main/sbbs/-/commit/2db618ae2da445cf21a420c5
Modified Files:
src/sbbs3/writemsg.cpp
Log Message:
Fix smb.subnum corruption in writemsg()
Fix issue introduced 9 years ago that could cause a crash after replying to a post via email or netmail and then displaying the header of a poll message or a normal message with votes:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f9f9569a317 in sbbs_t::show_msg (this=0x7f9f70c56880,
smb=0x7f9f70c5e4e0, msg=0x7f9ebadf08b0, p_mode=4, post=0x7f9f18071a24)
at getmsg.cpp:255
255 ,cfg.sub[smb->subnum]->misc&SUB_ NAME ? useron.name : useron.alias, NET_NONE, NULL);
[Current thread is 1 (Thread 0x7f9ebadf3700 (LWP 23279))]
(gdb) print smb->subnum
$1 = 4294967295
(gdb) bt
#0 0x00007f9f9569a317 in sbbs_t::show_msg (this=0x7f9f70c56880,
smb=0x7f9f70c5e4e0, msg=0x7f9ebadf08b0, p_mode=4, post=0x7f9f18071a24)
at getmsg.cpp:255
#1 0x00007f9f957b2aee in sbbs_t::scanposts (this=0x7f9f70c56880, subnum=9,
mode=2, find=0x7f9ebadf1270 "") at readmsgs.cpp:670
#2 0x00007f9f957bb75a in sbbs_t::scanallsubs (this=0x7f9f70c56880, mode=2)
at scansubs.cpp:219
#3 0x00007f9f9568c948 in sbbs_t::exec_msg (this=0x7f9f70c56880,
csi=0x7f9f70c64768) at execmsg.cpp:315
#4 0x00007f9f95683129 in sbbs_t::exec_function (this=0x7f9f70c56880,
csi=0x7f9f70c64768) at execfunc.cpp:422
#5 0x00007f9f95679450 in sbbs_t::exec (this=0x7f9f70c56880,
csi=0x7f9f70c64768) at exec.cpp:1199
#6 0x00007f9f9577d742 in node_thread (arg=0x7f9f70c56880) at main.cpp:4364
writemsg() was changing the global smb.subnum and when writing an email or netmail, that subnum value is -1 (since it's not a sub-board) and then later show_msg() is using the smb.subnum as a index into scfg.sub[] when determining if the current user already voted on the message being displayed and then: bang, crash, fall down, go boom.
Simply saving and restoring the smb.subnum when executing an external editor is all that was needed here. And this is the first use of the C++ "auto" keyword in Synchronet!
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