{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2021-47448", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix possible stall on recvmsg()\n\nrecvmsg() can enter an infinite loop if the caller provides the\nMSG_WAITALL, the data present in the receive queue is not sufficient to\nfulfill the request, and no more data is received by the peer.\n\nWhen the above happens, mptcp_wait_data() will always return with\nno wait, as the MPTCP_DATA_READY flag checked by such function is\nset and never cleared in such code path.\n\nLeveraging the above syzbot was able to trigger an RCU stall:\n\nrcu: INFO: rcu_preempt self-detected stall on CPU\nrcu: 0-...!: (10499 ticks this GP) idle=0af/1/0x4000000000000000 softirq=10678/10678 fqs=1\n (t=10500 jiffies g=13089 q=109)\nrcu: rcu_preempt kthread starved for 10497 jiffies! g13089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1\nrcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.\nrcu: RCU grace-period kthread stack dump:\ntask:rcu_preempt state:R running task stack:28696 pid: 14 ppid: 2 flags:0x00004000\nCall Trace:\n context_switch kernel/sched/core.c:4955 [inline]\n __schedule+0x940/0x26f0 kernel/sched/core.c:6236\n schedule+0xd3/0x270 kernel/sched/core.c:6315\n schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881\n rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955\n rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128\n kthread+0x405/0x4f0 kernel/kthread.c:327\n ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295\nrcu: Stack dump where RCU GP kthread last ran:\nSending NMI from CPU 0 to CPUs 1:\nNMI backtrace for cpu 1\nCPU: 1 PID: 8510 Comm: syz-executor827 Not tainted 5.15.0-rc2-next-20210920-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nRIP: 0010:bytes_is_nonzero mm/kasan/generic.c:84 [inline]\nRIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]\nRIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]\nRIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]\nRIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]\nRIP: 0010:kasan_check_range+0xc8/0x180 mm/kasan/generic.c:189\nCode: 38 00 74 ed 48 8d 50 08 eb 09 48 83 c0 01 48 39 d0 74 7a 80 38 00 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 <48> 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00\nRSP: 0018:ffffc9000cd676c8 EFLAGS: 00000283\nRAX: ffffed100e9a110e RBX: ffffed100e9a110f RCX: ffffffff88ea062a\nRDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888074d08870\nRBP: ffffed100e9a110e R08: 0000000000000001 R09: ffff888074d08877\nR10: ffffed100e9a110e R11: 0000000000000000 R12: ffff888074d08000\nR13: ffff888074d08000 R14: ffff888074d08088 R15: ffff888074d08000\nFS: 0000555556d8e300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000\nS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000020000180 CR3: 0000000068909000 CR4: 00000000001506e0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n instrument_atomic_read_write include/linux/instrumented.h:101 [inline]\n test_and_clear_bit include/asm-generic/bitops/instrumented-atomic.h:83 [inline]\n mptcp_release_cb+0x14a/0x210 net/mptcp/protocol.c:3016\n release_sock+0xb4/0x1b0 net/core/sock.c:3204\n mptcp_wait_data net/mptcp/protocol.c:1770 [inline]\n mptcp_recvmsg+0xfd1/0x27b0 net/mptcp/protocol.c:2080\n inet6_recvmsg+0x11b/0x5e0 net/ipv6/af_inet6.c:659\n sock_recvmsg_nosec net/socket.c:944 [inline]\n ____sys_recvmsg+0x527/0x600 net/socket.c:2626\n ___sys_recvmsg+0x127/0x200 net/socket.c:2670\n do_recvmmsg+0x24d/0x6d0 net/socket.c:2764\n __sys_recvmmsg net/socket.c:2843 [inline]\n __do_sys_recvmmsg net/socket.c:2866 [inline]\n __se_sys_recvmmsg net/socket.c:2859 [inline]\n __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2859\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x44/0xae\nRIP: 0033:0x7fc200d2\n---truncated---" } ] }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "n/a" } ] } ] }, "affects": { "vendor": { "vendor_data": [ { "vendor_name": "Linux", "product": { "product_data": [ { "product_name": "Linux", "version": { "version_data": [ { "version_affected": "<", "version_name": "7a6a6cbc3e59", "version_value": "1a4554e94f0d" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "custom" }, { "version": "5.14.14", "lessThanOrEqual": "5.14.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/1a4554e94f0deff9fc1dc5addf93fa579cc29711", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/1a4554e94f0deff9fc1dc5addf93fa579cc29711" }, { "url": "https://git.kernel.org/stable/c/612f71d7328c14369924384ad2170aae2a6abd92", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/612f71d7328c14369924384ad2170aae2a6abd92" } ] }, "generator": { "engine": "bippy-a5840b7849dd" } }