This is merely a historical archive of years 2008-2021, before the migration to mailman3.
A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/gerrit-log@lists.osmocom.org/.
Vadim Yanitskiy gerrit-no-reply at lists.osmocom.orgVadim Yanitskiy has submitted this change and it was merged. ( https://gerrit.osmocom.org/c/libosmocore/+/14973 ) Change subject: vty/vty.c: fix vty_read(): prevent further heap-buffer overrun ...................................................................... vty/vty.c: fix vty_read(): prevent further heap-buffer overrun After reading data from the socket, assigned to a given VTY, we need to '\0'-terminate the received string. Otherwise, further access to that string, stored in a heap buffer vty->buf, would lead to a heap overrun. == How to reproduce? $ python -c "print 'A' * 512" | telnet $HOST $PORT ==21264==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6190000211e0 at pc 0x000000435d2f bp 0x7ffc06c7add0 sp 0x7ffc06c7a578 READ of size 1025 at 0x6190000211e0 thread T0 #0 0x435d2e in __interceptor_strlen (/usr/local/bin/osmo-msc+0x435d2e) #1 0x7fb95bfa5624 in talloc_strdup (/usr/lib/x86_64-linux-gnu/libtalloc.so.2+0x6624) #2 0x7fb95c1be2bc in vty_hist_add /opt/osmocom/libosmocore/src/vty/vty.c:578 #3 0x7fb95c1be2bc in vty_execute /opt/osmocom/libosmocore/src/vty/vty.c:703 #4 0x7fb95c1be2bc in vty_read /opt/osmocom/libosmocore/src/vty/vty.c:1425 #5 0x7fb95c1bfd78 in client_data /opt/osmocom/libosmocore/src/vty/telnet_interface.c:157 #6 0x7fb95b90bd33 in osmo_fd_disp_fds /opt/osmocom/libosmocore/src/select.c:223 #7 0x7fb95b90bd33 in osmo_select_main /opt/osmocom/libosmocore/src/select.c:263 #8 0x5006cc in main /opt/osmocom/osmo-msc/src/osmo-msc/msc_main.c:723:3 #9 0x7fb959935f44 in __libc_start_main /build/eglibc-xkFqqE/eglibc-2.19/csu/libc-start.c:287 #10 0x4226fb in _start (/usr/local/bin/osmo-msc+0x4226fb) == Why exactly 512? Because the initial size of the heap buffer is 512 (see VTY_BUFSIZ). Later on it can be realloc()ated, so X > 512 should also work. Found using AddressSanitizer and Radamsa [1] fuzzer. [1] https://gitlab.com/akihe/radamsa Change-Id: I82f774ad18d0e555eb8f3590a519946d9c583c78 --- M src/vty/vty.c 1 file changed, 2 insertions(+), 0 deletions(-) Approvals: laforge: Looks good to me, but someone else must approve pespin: Looks good to me, approved Jenkins Builder: Verified diff --git a/src/vty/vty.c b/src/vty/vty.c index 98b332d..b1bb3f4 100644 --- a/src/vty/vty.c +++ b/src/vty/vty.c @@ -1416,6 +1416,8 @@ case '\n': case '\r': vty_out(vty, "%s", VTY_NEWLINE); + /* '\0'-terminate the command buffer */ + vty->buf[vty->length] = '\0'; vty_execute(vty); break; case '\t': -- To view, visit https://gerrit.osmocom.org/c/libosmocore/+/14973 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: libosmocore Gerrit-Branch: master Gerrit-Change-Id: I82f774ad18d0e555eb8f3590a519946d9c583c78 Gerrit-Change-Number: 14973 Gerrit-PatchSet: 4 Gerrit-Owner: Vadim Yanitskiy <axilirator at gmail.com> Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: Vadim Yanitskiy <axilirator at gmail.com> Gerrit-Reviewer: laforge <laforge at gnumonks.org> Gerrit-Reviewer: pespin <pespin at sysmocom.de> Gerrit-CC: neels <nhofmeyr at sysmocom.de> Gerrit-MessageType: merged -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.osmocom.org/pipermail/gerrit-log/attachments/20190730/0ab3cde0/attachment.htm>