5.4-stable review patch. If anyone has any objections, please let me know.
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From: Ivan Solodovnikov solodovnikov.ia@phystech.edu
[ Upstream commit 22be4727a8f898442066bcac34f8a1ad0bc72e14 ]
If dccp_feat_push_confirm() fails after new value for SP feature was accepted without reconciliation ('entry == NULL' branch), memory allocated for that value with dccp_feat_clone_sp_val() is never freed.
Here is the kmemleak stack for this:
unreferenced object 0xffff88801d4ab488 (size 8): comm "syz-executor310", pid 1127, jiffies 4295085598 (age 41.666s) hex dump (first 8 bytes): 01 b4 4a 1d 80 88 ff ff ..J..... backtrace: [<00000000db7cabfe>] kmemdup+0x23/0x50 mm/util.c:128 [<0000000019b38405>] kmemdup include/linux/string.h:465 [inline] [<0000000019b38405>] dccp_feat_clone_sp_val net/dccp/feat.c:371 [inline] [<0000000019b38405>] dccp_feat_clone_sp_val net/dccp/feat.c:367 [inline] [<0000000019b38405>] dccp_feat_change_recv net/dccp/feat.c:1145 [inline] [<0000000019b38405>] dccp_feat_parse_options+0x1196/0x2180 net/dccp/feat.c:1416 [<00000000b1f6d94a>] dccp_parse_options+0xa2a/0x1260 net/dccp/options.c:125 [<0000000030d7b621>] dccp_rcv_state_process+0x197/0x13d0 net/dccp/input.c:650 [<000000001f74c72e>] dccp_v4_do_rcv+0xf9/0x1a0 net/dccp/ipv4.c:688 [<00000000a6c24128>] sk_backlog_rcv include/net/sock.h:1041 [inline] [<00000000a6c24128>] __release_sock+0x139/0x3b0 net/core/sock.c:2570 [<00000000cf1f3a53>] release_sock+0x54/0x1b0 net/core/sock.c:3111 [<000000008422fa23>] inet_wait_for_connect net/ipv4/af_inet.c:603 [inline] [<000000008422fa23>] __inet_stream_connect+0x5d0/0xf70 net/ipv4/af_inet.c:696 [<0000000015b6f64d>] inet_stream_connect+0x53/0xa0 net/ipv4/af_inet.c:735 [<0000000010122488>] __sys_connect_file+0x15c/0x1a0 net/socket.c:1865 [<00000000b4b70023>] __sys_connect+0x165/0x1a0 net/socket.c:1882 [<00000000f4cb3815>] __do_sys_connect net/socket.c:1892 [inline] [<00000000f4cb3815>] __se_sys_connect net/socket.c:1889 [inline] [<00000000f4cb3815>] __x64_sys_connect+0x6e/0xb0 net/socket.c:1889 [<00000000e7b1e839>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 [<0000000055e91434>] entry_SYSCALL_64_after_hwframe+0x67/0xd1
Clean up the allocated memory in case of dccp_feat_push_confirm() failure and bail out with an error reset code.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: e77b8363b2ea ("dccp: Process incoming Change feature-negotiation options") Signed-off-by: Ivan Solodovnikov solodovnikov.ia@phystech.edu Link: https://patch.msgid.link/20241126143902.190853-1-solodovnikov.ia@phystech.ed... Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/dccp/feat.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/dccp/feat.c b/net/dccp/feat.c index 9c3b5e0562342..7647306802f1e 100644 --- a/net/dccp/feat.c +++ b/net/dccp/feat.c @@ -1156,8 +1156,12 @@ static u8 dccp_feat_change_recv(struct list_head *fn, u8 is_mandatory, u8 opt, goto not_valid_or_not_known; }
- return dccp_feat_push_confirm(fn, feat, local, &fval); + if (dccp_feat_push_confirm(fn, feat, local, &fval)) { + kfree(fval.sp.vec); + return DCCP_RESET_CODE_TOO_BUSY; + }
+ return 0; } else if (entry->state == FEAT_UNSTABLE) { /* 6.6.2 */ return 0; }