user/sven/linux.git/kernel/trace, branch v6.1.151

ftrace: Fix potential warning in trace_printk_seq during ftrace_dump

2025-09-04T13:26:24Z

[ Upstream commit 4013aef2ced9b756a410f50d12df9ebe6a883e4a ] When calling ftrace_dump_one() concurrently with reading trace_pipe, a WARN_ON_ONCE() in trace_printk_seq() can be triggered due to a race condition. The issue occurs because: CPU0 (ftrace_dump) CPU1 (reader) echo z > /proc/sysrq-trigger !trace_empty(&iter) trace_iterator_reset(&iter) <- len = size = 0 cat /sys/kernel/tracing/trace_pipe trace_find_next_entry_inc(&iter) __find_next_entry ring_buffer_empty_cpu <- all empty return NULL trace_printk_seq(&iter.seq) WARN_ON_ONCE(s->seq.len >= s->seq.size) In the context between trace_empty() and trace_find_next_entry_inc() during ftrace_dump, the ring buffer data was consumed by other readers. This caused trace_find_next_entry_inc to return NULL, failing to populate `iter.seq`. At this point, due to the prior trace_iterator_reset, both `iter.seq.len` and `iter.seq.size` were set to 0. Since they are equal, the WARN_ON_ONCE condition is triggered. Move the trace_printk_seq() into the if block that checks to make sure the return value of trace_find_next_entry_inc() is non-NULL in ftrace_dump_one(), ensuring the 'iter.seq' is properly populated before subsequent operations. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Ingo Molnar Link: https://lore.kernel.org/20250822033343.3000289-1-wutengda@huaweicloud.com Fixes: d769041f8653 ("ring_buffer: implement new locking") Signed-off-by: Tengda Wu Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

tracing: Limit access to parser->buffer when trace_get_user failed

2025-08-28T14:26:16Z

[ Upstream commit 6a909ea83f226803ea0e718f6e88613df9234d58 ] When the length of the string written to set_ftrace_filter exceeds FTRACE_BUFF_MAX, the following KASAN alarm will be triggered: BUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0 Read of size 1 at addr ffff0000d00bd5ba by task ash/165 CPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x34/0x50 (C) dump_stack_lvl+0xa0/0x158 print_address_description.constprop.0+0x88/0x398 print_report+0xb0/0x280 kasan_report+0xa4/0xf0 __asan_report_load1_noabort+0x20/0x30 strsep+0x18c/0x1b0 ftrace_process_regex.isra.0+0x100/0x2d8 ftrace_regex_release+0x484/0x618 __fput+0x364/0xa58 ____fput+0x28/0x40 task_work_run+0x154/0x278 do_notify_resume+0x1f0/0x220 el0_svc+0xec/0xf0 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 The reason is that trace_get_user will fail when processing a string longer than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0. Then an OOB access will be triggered in ftrace_regex_release-> ftrace_process_regex->strsep->strpbrk. We can solve this problem by limiting access to parser->buffer when trace_get_user failed. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20250813040232.1344527-1-pulehui@huaweicloud.com Fixes: 8c9af478c06b ("ftrace: Handle commands when closing set_ftrace_filter file") Signed-off-by: Pu Lehui Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

tracing: Remove unneeded goto out logic

2025-08-28T14:26:16Z

[ Upstream commit c89504a703fb779052213add0e8ed642f4a4f1c8 ] Several places in the trace.c file there's a goto out where the out is simply a return. There's no reason to jump to the out label if it's not doing any more logic but simply returning from the function. Replace the goto outs with a return and remove the out labels. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Link: https://lore.kernel.org/20250801203857.538726745@kernel.org Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ftrace: Also allocate and copy hash for reading of filter files

2025-08-28T14:26:14Z

commit bfb336cf97df7b37b2b2edec0f69773e06d11955 upstream. Currently the reader of set_ftrace_filter and set_ftrace_notrace just adds the pointer to the global tracer hash to its iterator. Unlike the writer that allocates a copy of the hash, the reader keeps the pointer to the filter hashes. This is problematic because this pointer is static across function calls that release the locks that can update the global tracer hashes. This can cause UAF and similar bugs. Allocate and copy the hash for reading the filter files like it is done for the writers. This not only fixes UAF bugs, but also makes the code a bit simpler as it doesn't have to differentiate when to free the iterator's hash between writers and readers. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Nathan Chancellor Cc: Linus Torvalds Link: https://lore.kernel.org/20250822183606.12962cc3@batman.local.home Fixes: c20489dad156 ("ftrace: Assign iter->hash to filter or notrace hashes on seq read") Closes: https://lore.kernel.org/all/20250813023044.2121943-1-wutengda@huaweicloud.com/ Closes: https://lore.kernel.org/all/20250822192437.GA458494@ax162/ Reported-by: Tengda Wu Tested-by: Tengda Wu Tested-by: Nathan Chancellor Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

kernel: trace: preemptirq_delay_test: use offstack cpu mask

2025-08-15T10:05:02Z

[ Upstream commit adc353c0bfb243ebfd29b6222fa3bf149169a6de ] A CPU mask on the stack is broken for large values of CONFIG_NR_CPUS: kernel/trace/preemptirq_delay_test.c: In function ‘preemptirq_delay_run’: kernel/trace/preemptirq_delay_test.c:143:1: error: the frame size of 8512 bytes is larger than 1536 bytes [-Werror=frame-larger-than=] Fall back to dynamic allocation here. Cc: Masami Hiramatsu Cc: Song Chen Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20250620111215.3365305-1-arnd@kernel.org Fixes: 4b9091e1c194 ("kernel: trace: preemptirq_delay_test: add cpu affinity") Signed-off-by: Arnd Bergmann Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

tracing: Add down_write(trace_event_sem) when adding trace event

2025-07-24T06:51:48Z

commit b5e8acc14dcb314a9b61ff19dcd9fdd0d88f70df upstream. When a module is loaded, it adds trace events defined by the module. It may also need to modify the modules trace printk formats to replace enum names with their values. If two modules are loaded at the same time, the adding of the event to the ftrace_events list can corrupt the walking of the list in the code that is modifying the printk format strings and crash the kernel. The addition of the event should take the trace_event_sem for write while it adds the new event. Also add a lockdep_assert_held() on that semaphore in __trace_add_event_dirs() as it iterates the list. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/20250718223158.799bfc0c@batman.local.home Reported-by: Fusheng Huang(黄富生) Closes: https://lore.kernel.org/all/20250717105007.46ccd18f@batman.local.home/ Fixes: 110bf2b764eb6 ("tracing: add protection around module events unload") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

ftrace: Fix UAF when lookup kallsym after ftrace disabled

2025-06-27T10:07:30Z

commit f914b52c379c12288b7623bb814d0508dbe7481d upstream. The following issue happens with a buggy module: BUG: unable to handle page fault for address: ffffffffc05d0218 PGD 1bd66f067 P4D 1bd66f067 PUD 1bd671067 PMD 101808067 PTE 0 Oops: Oops: 0000 [#1] SMP KASAN PTI Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS RIP: 0010:sized_strscpy+0x81/0x2f0 RSP: 0018:ffff88812d76fa08 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffffc0601010 RCX: dffffc0000000000 RDX: 0000000000000038 RSI: dffffc0000000000 RDI: ffff88812608da2d RBP: 8080808080808080 R08: ffff88812608da2d R09: ffff88812608da68 R10: ffff88812608d82d R11: ffff88812608d810 R12: 0000000000000038 R13: ffff88812608da2d R14: ffffffffc05d0218 R15: fefefefefefefeff FS: 00007fef552de740(0000) GS:ffff8884251c7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffc05d0218 CR3: 00000001146f0000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ftrace_mod_get_kallsym+0x1ac/0x590 update_iter_mod+0x239/0x5b0 s_next+0x5b/0xa0 seq_read_iter+0x8c9/0x1070 seq_read+0x249/0x3b0 proc_reg_read+0x1b0/0x280 vfs_read+0x17f/0x920 ksys_read+0xf3/0x1c0 do_syscall_64+0x5f/0x2e0 entry_SYSCALL_64_after_hwframe+0x76/0x7e The above issue may happen as follows: (1) Add kprobe tracepoint; (2) insmod test.ko; (3) Module triggers ftrace disabled; (4) rmmod test.ko; (5) cat /proc/kallsyms; --> Will trigger UAF as test.ko already removed; ftrace_mod_get_kallsym() ... strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); ... The problem is when a module triggers an issue with ftrace and sets ftrace_disable. The ftrace_disable is set when an anomaly is discovered and to prevent any more damage, ftrace stops all text modification. The issue that happened was that the ftrace_disable stops more than just the text modification. When a module is loaded, its init functions can also be traced. Because kallsyms deletes the init functions after a module has loaded, ftrace saves them when the module is loaded and function tracing is enabled. This allows the output of the function trace to show the init function names instead of just their raw memory addresses. When a module is removed, ftrace_release_mod() is called, and if ftrace_disable is set, it just returns without doing anything more. The problem here is that it leaves the mod_list still around and if kallsyms is called, it will call into this code and access the module memory that has already been freed as it will return: strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); Where the "mod" no longer exists and triggers a UAF bug. Link: https://lore.kernel.org/all/20250523135452.626d8dcd@gandalf.local.home/ Cc: stable@vger.kernel.org Fixes: aba4b5c22cba ("ftrace: Save module init functions kallsyms symbols for tracing") Link: https://lore.kernel.org/20250529111955.2349189-2-yebin@huaweicloud.com Signed-off-by: Ye Bin Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

bpf: Fix WARN() in get_bpf_raw_tp_regs

2025-06-27T10:07:11Z

[ Upstream commit 3880cdbed1c4607e378f58fa924c5d6df900d1d3 ] syzkaller reported an issue: WARNING: CPU: 3 PID: 5971 at kernel/trace/bpf_trace.c:1861 get_bpf_raw_tp_regs+0xa4/0x100 kernel/trace/bpf_trace.c:1861 Modules linked in: CPU: 3 UID: 0 PID: 5971 Comm: syz-executor205 Not tainted 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:get_bpf_raw_tp_regs+0xa4/0x100 kernel/trace/bpf_trace.c:1861 RSP: 0018:ffffc90003636fa8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff81c6bc4c RDX: ffff888032efc880 RSI: ffffffff81c6bc83 RDI: 0000000000000005 RBP: ffff88806a730860 R08: 0000000000000005 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000004 R13: 0000000000000001 R14: ffffc90003637008 R15: 0000000000000900 FS: 0000000000000000(0000) GS:ffff8880d6cdf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7baee09130 CR3: 0000000029f5a000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1934 [inline] bpf_get_stack_raw_tp+0x24/0x160 kernel/trace/bpf_trace.c:1931 bpf_prog_ec3b2eefa702d8d3+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline] bpf_trace_run3+0x23f/0x5a0 kernel/trace/bpf_trace.c:2405 __bpf_trace_mmap_lock_acquire_returned+0xfc/0x140 include/trace/events/mmap_lock.h:47 __traceiter_mmap_lock_acquire_returned+0x79/0xc0 include/trace/events/mmap_lock.h:47 __do_trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:47 [inline] trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:47 [inline] __mmap_lock_do_trace_acquire_returned+0x138/0x1f0 mm/mmap_lock.c:35 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:204 [inline] stack_map_get_build_id_offset+0x535/0x6f0 kernel/bpf/stackmap.c:157 __bpf_get_stack+0x307/0xa10 kernel/bpf/stackmap.c:483 ____bpf_get_stack kernel/bpf/stackmap.c:499 [inline] bpf_get_stack+0x32/0x40 kernel/bpf/stackmap.c:496 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1941 [inline] bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1931 bpf_prog_ec3b2eefa702d8d3+0x43/0x47 Tracepoint like trace_mmap_lock_acquire_returned may cause nested call as the corner case show above, which will be resolved with more general method in the future. As a result, WARN_ON_ONCE will be triggered. As Alexei suggested, remove the WARN_ON_ONCE first. Fixes: 9594dc3c7e71 ("bpf: fix nested bpf tracepoints with per-cpu data") Reported-by: syzbot+45b0c89a0fc7ae8dbadc@syzkaller.appspotmail.com Suggested-by: Alexei Starovoitov Signed-off-by: Tao Chen Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250513042747.757042-1-chen.dylane@linux.dev Closes: https://lore.kernel.org/bpf/8bc2554d-1052-4922-8832-e0078a033e1d@gmail.com Signed-off-by: Sasha Levin

tracing: Fix error handling in event_trigger_parse()

2025-06-27T10:07:10Z

[ Upstream commit c5dd28e7fb4f63475b50df4f58311df92939d011 ] According to trigger_data_alloc() doc, trigger_data_free() should be used to free an event_trigger_data object. This fixes a mismatch introduced when kzalloc was replaced with trigger_data_alloc without updating the corresponding deallocation calls. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Andrew Morton Cc: Mathieu Desnoyers Cc: Tom Zanussi Link: https://lore.kernel.org/20250507145455.944453325@goodmis.org Link: https://lore.kernel.org/20250318112737.4174-1-linmq006@gmail.com Fixes: e1f187d09e11 ("tracing: Have existing event_command.parse() implementations use helpers") Signed-off-by: Miaoqian Lin [ SDR: Changed event_trigger_alloc/free() to trigger_data_alloc/free() ] Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

tracing: Rename event_trigger_alloc() to trigger_data_alloc()

2025-06-27T10:07:10Z

[ Upstream commit f2947c4b7d0f235621c5daf78aecfbd6e22c05e5 ] The function event_trigger_alloc() creates an event_trigger_data descriptor and states that it needs to be freed via event_trigger_free(). This is incorrect, it needs to be freed by trigger_data_free() as event_trigger_free() adds ref counting. Rename event_trigger_alloc() to trigger_data_alloc() and state that it needs to be freed via trigger_data_free(). This naming convention was introducing bugs. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Tom Zanussi Link: https://lore.kernel.org/20250507145455.776436410@goodmis.org Fixes: 86599dbe2c527 ("tracing: Add helper functions to simplify event_command.parse() callback handling") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin