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AJvYcCWUHpICw5ZZj4aL3bqzeYpveZpe1f0vCtzl3UaDwHIU6jcH4HVclQvX6nwIEpoGTBA39RwJSYY+LsleaGE=@vger.kernel.org X-Gm-Message-State: AOJu0Yze1qi7iitxb+B/UXcCpPh0YHMW3+XkIgj/OtAax4lwkPV42NUQ Ai4yJ++AybOEvRr9qlD/SkX2APmx7TVuIU4KIpz4iK2/zz72grShtTY662//OmC+HKoLlcKTs5e 9zg6w/46iXXUZXWcqd39XekoHXX5sY9PmUtx8zPsKA3FhDD7wKxpfBt952rk= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:c14c:b0:467:1880:ffb9 with SMTP id 5614622812f47-467572d39bamr9428527b6e.40.1773729927311; Mon, 16 Mar 2026 23:45:27 -0700 (PDT) Date: Mon, 16 Mar 2026 23:45:27 -0700 In-Reply-To: <69343e08.a70a0220.38f243.002c.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69b8f887.050a0220.248e02.0127.GAE@google.com> Subject: Re: [syzbot] [bpf?] KMSAN: uninit-value in handle_bug From: syzbot To: andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, eddyz87@gmail.com, haoluo@google.com, john.fastabend@gmail.com, jolsa@kernel.org, kpsingh@kernel.org, linux-kernel@vger.kernel.org, martin.lau@linux.dev, sdf@fomichev.me, song@kernel.org, syzkaller-bugs@googlegroups.com, yonghong.song@linux.dev Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 2d1373e4246d Merge tag 'for-7.0-rc4-tag' of git://git.kern.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=146bc4da580000 kernel config: https://syzkaller.appspot.com/x/.config?x=963de479f54c6dbb dashboard link: https://syzkaller.appspot.com/bug?extid=ba80855313e6fa65717a compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14b4a8da580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16773406580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/bef78207d3f7/disk-2d1373e4.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/35fd28ca5034/vmlinux-2d1373e4.xz kernel image: https://storage.googleapis.com/syzbot-assets/c2b759faae9e/bzImage-2d1373e4.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ba80855313e6fa65717a@syzkaller.appspotmail.com ------------[ cut here ]------------ ===================================================== BUG: KMSAN: uninit-value in vsnprintf+0x15be/0x1b00 lib/vsprintf.c:2912 vsnprintf+0x15be/0x1b00 lib/vsprintf.c:2912 vprintk_store+0x350/0x1550 kernel/printk/printk.c:2307 vprintk_emit+0x2c8/0xba0 kernel/printk/printk.c:2455 vprintk_default+0x3f/0x50 kernel/printk/printk.c:2494 vprintk+0x36/0x50 kernel/printk/printk_safe.c:82 __warn_printf lib/bug.c:190 [inline] __report_bug+0xa10/0xe00 lib/bug.c:244 report_bug_entry+0x17c/0x220 lib/bug.c:269 handle_bug+0xe5/0x230 arch/x86/kernel/traps.c:430 exc_invalid_op+0x1f/0x50 arch/x86/kernel/traps.c:489 asm_exc_invalid_op+0x1f/0x30 arch/x86/include/asm/idtentry.h:616 reg_bounds_sanity_check+0x571/0x14e0 kernel/bpf/verifier.c:2817 reg_set_min_max+0x34b/0x450 kernel/bpf/verifier.c:17159 check_cond_jmp_op+0x3bf5/0x5370 kernel/bpf/verifier.c:17609 do_check_insn kernel/bpf/verifier.c:21168 [inline] do_check+0xc7e8/0x1add0 kernel/bpf/verifier.c:21308 do_check_common+0x2705/0x4270 kernel/bpf/verifier.c:24650 do_check_main kernel/bpf/verifier.c:24733 [inline] bpf_check+0x1f159/0x27e90 kernel/bpf/verifier.c:26056 bpf_prog_load+0x2b41/0x3140 kernel/bpf/syscall.c:3089 __sys_bpf+0x8e0/0xee0 kernel/bpf/syscall.c:6228 __do_sys_bpf kernel/bpf/syscall.c:6341 [inline] __se_sys_bpf kernel/bpf/syscall.c:6339 [inline] __x64_sys_bpf+0xa4/0xf0 kernel/bpf/syscall.c:6339 x64_sys_call+0x13d0/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x134/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: vsnprintf+0x15b7/0x1b00 lib/vsprintf.c:-1 vprintk_store+0x350/0x1550 kernel/printk/printk.c:2307 vprintk_emit+0x2c8/0xba0 kernel/printk/printk.c:2455 vprintk_default+0x3f/0x50 kernel/printk/printk.c:2494 vprintk+0x36/0x50 kernel/printk/printk_safe.c:82 __warn_printf lib/bug.c:190 [inline] __report_bug+0xa10/0xe00 lib/bug.c:244 report_bug_entry+0x17c/0x220 lib/bug.c:269 handle_bug+0xe5/0x230 arch/x86/kernel/traps.c:430 exc_invalid_op+0x1f/0x50 arch/x86/kernel/traps.c:489 asm_exc_invalid_op+0x1f/0x30 arch/x86/include/asm/idtentry.h:616 Local variable pflags created at: try_charge_memcg+0x63/0x1c20 mm/memcontrol.c:2367 obj_cgroup_charge_pages+0x69/0x330 mm/memcontrol.c:2857 CPU: 1 UID: 0 PID: 5997 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 ===================================================== --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.