{"cve":"CVE-2024-42076","nvd":{"published":"2024-07-29T16:15:06.960","modified":"2026-06-17T07:48:45.470","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: can: j1939: Initialize unused data in j1939_send_one()\n\nsyzbot reported kernel-infoleak in raw_recvmsg() [1]. j1939_send_one()\ncreates full frame including unused data, but it doesn't initialize\nit. This causes the kernel-infoleak issue. Fix this by initializing\nunused data.\n\n[1]\nBUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]\nBUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline]\nBUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:29 [inline]\nBUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:245 [inline]\nBUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:271 [inline]\nBUG: KMSAN: kernel-infoleak in _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185\n instrument_copy_to_user include/linux/instrumented.h:114 [inline]\n copy_to_user_iter lib/iov_iter.c:24 [inline]\n iterate_ubuf include/linux/iov_iter.h:29 [inline]\n iterate_and_advance2 include/linux/iov_iter.h:245 [inline]\n iterate_and_advance include/linux/iov_iter.h:271 [inline]\n _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185\n copy_to_iter include/linux/uio.h:196 [inline]\n memcpy_to_msg include/linux/skbuff.h:4113 [inline]\n raw_recvmsg+0x2b8/0x9e0 net/can/raw.c:1008\n sock_recvmsg_nosec net/socket.c:1046 [inline]\n sock_recvmsg+0x2c4/0x340 net/socket.c:1068\n ____sys_recvmsg+0x18a/0x620 net/socket.c:2803\n ___sys_recvmsg+0x223/0x840 net/socket.c:2845\n do_recvmmsg+0x4fc/0xfd0 net/socket.c:2939\n __sys_recvmmsg net/socket.c:3018 [inline]\n __do_sys_recvmmsg net/socket.c:3041 [inline]\n __se_sys_recvmmsg net/socket.c:3034 [inline]\n __x64_sys_recvmmsg+0x397/0x490 net/socket.c:3034\n x64_sys_call+0xf6c/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:300\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nUninit was created at:\n slab_post_alloc_hook mm/slub.c:3804 [inline]\n slab_alloc_node mm/slub.c:3845 [inline]\n kmem_cache_alloc_node+0x613/0xc50 mm/slub.c:3888\n kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577\n __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668\n alloc_skb include/linux/skbuff.h:1313 [inline]\n alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504\n sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795\n sock_alloc_send_skb include/net/sock.h:1842 [inline]\n j1939_sk_alloc_skb net/can/j1939/socket.c:878 [inline]\n j1939_sk_send_loop net/can/j1939/socket.c:1142 [inline]\n j1939_sk_sendmsg+0xc0a/0x2730 net/can/j1939/socket.c:1277\n sock_sendmsg_nosec net/socket.c:730 [inline]\n __sock_sendmsg+0x30f/0x380 net/socket.c:745\n ____sys_sendmsg+0x877/0xb60 net/socket.c:2584\n ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638\n __sys_sendmsg net/socket.c:2667 [inline]\n __do_sys_sendmsg net/socket.c:2676 [inline]\n __se_sys_sendmsg net/socket.c:2674 [inline]\n __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2674\n x64_sys_call+0xc4b/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:47\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nBytes 12-15 of 16 are uninitialized\nMemory access of size 16 starts at ffff888120969690\nData copied to user address 00000000200017c0\n\nCPU: 1 PID: 5050 Comm: syz-executor198 Not tainted 6.9.0-rc5-syzkaller-00031-g71b1543c83d6 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-908"],"references":["https://git.kernel.org/stable/c/4c5dc3927e17489c1cae6f48c0d5e4acb4cae01f","https://git.kernel.org/stable/c/5e4ed38eb17eaca42de57d500cc0f9668d2b6abf","https://git.kernel.org/stable/c/a2a0ebff7fdeb2f66e29335adf64b9e457300dd4","https://git.kernel.org/stable/c/ab2a683938ba4416d389c2f5651cbbb2c41b779f","https://git.kernel.org/stable/c/b7cdf1dd5d2a2d8200efd98d1893684db48fe134"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:53:51.317825789+00:00"},"epss":{"cve":"CVE-2024-42076","score":0.00225,"percentile":0.13269,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}