From: Jeremy Allison Date: Thu, 13 Jul 2017 19:06:58 +0000 (-0700) Subject: s3: smbd: Fix a read after free if a chained SMB1 call goes async. X-Git-Url: http://git.samba.org/?p=metze%2Fsamba%2Fwip.git;a=commitdiff_plain;h=5fe76a5474823ed7602938a07c9c43226a7882a3 s3: smbd: Fix a read after free if a chained SMB1 call goes async. Reported to the Samba Team by Yihan Lian , a security researcher of Qihoo 360 GearTeam. Thanks a lot! smb1_parse_chain() incorrectly used talloc_tos() for the memory context of the chained smb1 requests. This gets freed between requests so if a chained request goes async, the saved request array also is freed, which causes a crash on resume. BUG: https://bugzilla.samba.org/show_bug.cgi?id=12836 Signed-off-by: Jeremy Allison Reviewed-by: Stefan Metzmacher --- diff --git a/source3/smbd/process.c b/source3/smbd/process.c index a19b8b78b9b7..3765739d9c4e 100644 --- a/source3/smbd/process.c +++ b/source3/smbd/process.c @@ -1785,7 +1785,7 @@ static void construct_reply_chain(struct smbXsrv_connection *xconn, unsigned num_reqs; bool ok; - ok = smb1_parse_chain(talloc_tos(), (uint8_t *)inbuf, xconn, encrypted, + ok = smb1_parse_chain(xconn, (uint8_t *)inbuf, xconn, encrypted, seqnum, &reqs, &num_reqs); if (!ok) { char errbuf[smb_size];