{"id":"CVE-2024-42076","summary":"net: can: j1939: Initialize unused data in j1939_send_one()","details":"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","modified":"2026-04-02T12:17:43.363685Z","published":"2024-07-29T15:52:38.981Z","related":["SUSE-SU-2024:3190-1","SUSE-SU-2024:3194-1","SUSE-SU-2024:3195-1","SUSE-SU-2024:3209-1","SUSE-SU-2024:3383-1","SUSE-SU-2024:3483-1","SUSE-SU-2025:20044-1","SUSE-SU-2025:20047-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/42xxx/CVE-2024-42076.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/4c5dc3927e17489c1cae6f48c0d5e4acb4cae01f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5e4ed38eb17eaca42de57d500cc0f9668d2b6abf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a2a0ebff7fdeb2f66e29335adf64b9e457300dd4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ab2a683938ba4416d389c2f5651cbbb2c41b779f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b7cdf1dd5d2a2d8200efd98d1893684db48fe134"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ba7e5ae8208ac07d8e1eace0951a34c169a2d298"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f97cbce633923588307049c4aef9feb2987e371b"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/42xxx/CVE-2024-42076.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-42076"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9d71dd0c70099914fcd063135da3c580865e924c"},{"fixed":"5e4ed38eb17eaca42de57d500cc0f9668d2b6abf"},{"fixed":"a2a0ebff7fdeb2f66e29335adf64b9e457300dd4"},{"fixed":"4c5dc3927e17489c1cae6f48c0d5e4acb4cae01f"},{"fixed":"f97cbce633923588307049c4aef9feb2987e371b"},{"fixed":"ab2a683938ba4416d389c2f5651cbbb2c41b779f"},{"fixed":"ba7e5ae8208ac07d8e1eace0951a34c169a2d298"},{"fixed":"b7cdf1dd5d2a2d8200efd98d1893684db48fe134"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-42076.json"}}],"schema_version":"1.7.5"}