From b80091b0113c931894c87b034048f8677a53fe9f Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Tue, 24 Jul 2018 19:13:31 -0400 Subject: tracing: Fix double free of event_trigger_data commit 1863c387259b629e4ebfb255495f67cd06aa229b upstream. Running the following: # cd /sys/kernel/debug/tracing # echo 500000 > buffer_size_kb [ Or some other number that takes up most of memory ] # echo snapshot > events/sched/sched_switch/trigger Triggers the following bug: ------------[ cut here ]------------ kernel BUG at mm/slub.c:296! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI CPU: 6 PID: 6878 Comm: bash Not tainted 4.18.0-rc6-test+ #1066 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:kfree+0x16c/0x180 Code: 05 41 0f b6 72 51 5b 5d 41 5c 4c 89 d7 e9 ac b3 f8 ff 48 89 d9 48 89 da 41 b8 01 00 00 00 5b 5d 41 5c 4c 89 d6 e9 f4 f3 ff ff <0f> 0b 0f 0b 48 8b 3d d9 d8 f9 00 e9 c1 fe ff ff 0f 1f 40 00 0f 1f RSP: 0018:ffffb654436d3d88 EFLAGS: 00010246 RAX: ffff91a9d50f3d80 RBX: ffff91a9d50f3d80 RCX: ffff91a9d50f3d80 RDX: 00000000000006a4 RSI: ffff91a9de5a60e0 RDI: ffff91a9d9803500 RBP: ffffffff8d267c80 R08: 00000000000260e0 R09: ffffffff8c1a56be R10: fffff0d404543cc0 R11: 0000000000000389 R12: ffffffff8c1a56be R13: ffff91a9d9930e18 R14: ffff91a98c0c2890 R15: ffffffff8d267d00 FS: 00007f363ea64700(0000) GS:ffff91a9de580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c1cacc8e10 CR3: 00000000d9b46003 CR4: 00000000001606e0 Call Trace: event_trigger_callback+0xee/0x1d0 event_trigger_write+0xfc/0x1a0 __vfs_write+0x33/0x190 ? handle_mm_fault+0x115/0x230 ? _cond_resched+0x16/0x40 vfs_write+0xb0/0x190 ksys_write+0x52/0xc0 do_syscall_64+0x5a/0x160 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f363e16ab50 Code: 73 01 c3 48 8b 0d 38 83 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 79 db 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e e3 01 00 48 89 04 24 RSP: 002b:00007fff9a4c6378 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f363e16ab50 RDX: 0000000000000009 RSI: 000055c1cacc8e10 RDI: 0000000000000001 RBP: 000055c1cacc8e10 R08: 00007f363e435740 R09: 00007f363ea64700 R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000009 R13: 0000000000000001 R14: 00007f363e4345e0 R15: 00007f363e4303c0 Modules linked in: ip6table_filter ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device i915 snd_pcm snd_timer i2c_i801 snd soundcore i2c_algo_bit drm_kms_helper 86_pkg_temp_thermal video kvm_intel kvm irqbypass wmi e1000e ---[ end trace d301afa879ddfa25 ]--- The cause is because the register_snapshot_trigger() call failed to allocate the snapshot buffer, and then called unregister_trigger() which freed the data that was passed to it. Then on return to the function that called register_snapshot_trigger(), as it sees it failed to register, it frees the trigger_data again and causes a double free. By calling event_trigger_init() on the trigger_data (which only ups the reference counter for it), and then event_trigger_free() afterward, the trigger_data would not get freed by the registering trigger function as it would only up and lower the ref count for it. If the register trigger function fails, then the event_trigger_free() called after it will free the trigger data normally. Link: http://lkml.kernel.org/r/20180724191331.738eb819@gandalf.local.home Cc: stable@vger.kerne.org Fixes: 93e31ffbf417 ("tracing: Add 'snapshot' event trigger command") Reported-by: Masami Hiramatsu Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events_trigger.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 2172dd61577e..9d9cacf07ed4 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -663,6 +663,8 @@ event_trigger_callback(struct event_command *cmd_ops, goto out_free; out_reg: + /* Up the trigger_data count to make sure reg doesn't free it on failure */ + event_trigger_init(trigger_ops, trigger_data); ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); /* * The above returns on success the # of functions enabled, @@ -670,11 +672,13 @@ event_trigger_callback(struct event_command *cmd_ops, * Consider no functions a failure too. */ if (!ret) { + cmd_ops->unreg(glob, trigger_ops, trigger_data, file); ret = -ENOENT; - goto out_free; - } else if (ret < 0) - goto out_free; - ret = 0; + } else if (ret > 0) + ret = 0; + + /* Down the counter of trigger_data or free it if not used anymore */ + event_trigger_free(trigger_ops, trigger_data); out: return ret; -- cgit v1.2.3 From 1a7f63b2a0911df09b4939995e3fe5daeb9753ef Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 25 Jul 2018 16:02:06 -0400 Subject: tracing: Fix possible double free in event_enable_trigger_func() commit 15cc78644d0075e76d59476a4467e7143860f660 upstream. There was a case that triggered a double free in event_trigger_callback() due to the called reg() function freeing the trigger_data and then it getting freed again by the error return by the caller. The solution there was to up the trigger_data ref count. Code inspection found that event_enable_trigger_func() has the same issue, but is not as easy to trigger (requires harder to trigger failures). It needs to be solved slightly different as it needs more to clean up when the reg() function fails. Link: http://lkml.kernel.org/r/20180725124008.7008e586@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 7862ad1846e99 ("tracing: Add 'enable_event' and 'disable_event' event trigger commands") Reivewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events_trigger.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 9d9cacf07ed4..b8a894adab2c 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1231,6 +1231,9 @@ event_enable_trigger_func(struct event_command *cmd_ops, goto out; } + /* Up the trigger_data count to make sure nothing frees it on failure */ + event_trigger_init(trigger_ops, trigger_data); + if (trigger) { number = strsep(&trigger, ":"); @@ -1281,6 +1284,7 @@ event_enable_trigger_func(struct event_command *cmd_ops, goto out_disable; /* Just return zero, not the number of enabled functions */ ret = 0; + event_trigger_free(trigger_ops, trigger_data); out: return ret; @@ -1291,7 +1295,7 @@ event_enable_trigger_func(struct event_command *cmd_ops, out_free: if (cmd_ops->set_filter) cmd_ops->set_filter(NULL, trigger_data, NULL); - kfree(trigger_data); + event_trigger_free(trigger_ops, trigger_data); kfree(enable_data); goto out; } -- cgit v1.2.3 From d9bbd8076836b1c3e648132afe73185f945b89a7 Mon Sep 17 00:00:00 2001 From: Artem Savkov Date: Wed, 25 Jul 2018 16:20:38 +0200 Subject: tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure commit 57ea2a34adf40f3a6e88409aafcf803b8945619a upstream. If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe it returns an error, but does not unset the tp flags it set previously. This results in a probe being considered enabled and failures like being unable to remove the probe through kprobe_events file since probes_open() expects every probe to be disabled. Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com Cc: Ingo Molnar Cc: stable@vger.kernel.org Fixes: 41a7dd420c57 ("tracing/kprobes: Support ftrace_event_file base multibuffer") Acked-by: Masami Hiramatsu Reviewed-by: Josh Poimboeuf Signed-off-by: Artem Savkov Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_kprobe.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f2682799c215..a357d7e93934 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -349,11 +349,10 @@ static struct trace_kprobe *find_trace_kprobe(const char *event, static int enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) { + struct event_file_link *link; int ret = 0; if (file) { - struct event_file_link *link; - link = kmalloc(sizeof(*link), GFP_KERNEL); if (!link) { ret = -ENOMEM; @@ -373,6 +372,16 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) else ret = enable_kprobe(&tk->rp.kp); } + + if (ret) { + if (file) { + list_del_rcu(&link->list); + kfree(link); + tk->tp.flags &= ~TP_FLAG_TRACE; + } else { + tk->tp.flags &= ~TP_FLAG_PROFILE; + } + } out: return ret; } -- cgit v1.2.3 From dab04fda26530ee686b14b02aa2c5e716cef153c Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 25 Jul 2018 22:28:56 -0400 Subject: tracing: Quiet gcc warning about maybe unused link variable commit 2519c1bbe38d7acacc9aacba303ca6f97482ed53 upstream. Commit 57ea2a34adf4 ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure") added an if statement that depends on another if statement that gcc doesn't see will initialize the "link" variable and gives the warning: "warning: 'link' may be used uninitialized in this function" It is really a false positive, but to quiet the warning, and also to make sure that it never actually is used uninitialized, initialize the "link" variable to NULL and add an if (!WARN_ON_ONCE(!link)) where the compiler thinks it could be used uninitialized. Cc: stable@vger.kernel.org Fixes: 57ea2a34adf4 ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure") Reported-by: kbuild test robot Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_kprobe.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index a357d7e93934..f0ee722be520 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -349,7 +349,7 @@ static struct trace_kprobe *find_trace_kprobe(const char *event, static int enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) { - struct event_file_link *link; + struct event_file_link *link = NULL; int ret = 0; if (file) { @@ -375,7 +375,9 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) if (ret) { if (file) { - list_del_rcu(&link->list); + /* Notice the if is true on not WARN() */ + if (!WARN_ON_ONCE(!link)) + list_del_rcu(&link->list); kfree(link); tk->tp.flags &= ~TP_FLAG_TRACE; } else { -- cgit v1.2.3 From b23dab51e987787e358397b24831505668625b8a Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 3 May 2018 18:37:17 -0700 Subject: bpf: fix references to free_bpf_prog_info() in comments [ Upstream commit ab7f5bf0928be2f148d000a6eaa6c0a36e74750e ] Comments in the verifier refer to free_bpf_prog_info() which seems to have never existed in tree. Replace it with free_used_maps(). Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/verifier.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 79e3c21a35d0..35dfa9e9d69e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2101,7 +2101,7 @@ static int replace_map_fd_with_map_ptr(struct verifier_env *env) /* hold the map. If the program is rejected by verifier, * the map will be released by release_maps() or it * will be used by the valid program until it's unloaded - * and all maps are released in free_bpf_prog_info() + * and all maps are released in free_used_maps() */ map = bpf_map_inc(map, false); if (IS_ERR(map)) { @@ -2487,7 +2487,7 @@ free_log_buf: vfree(log_buf); if (!env->prog->aux->used_maps) /* if we didn't copy map pointers into bpf_prog_info, release - * them now. Otherwise free_bpf_prog_info() will release them. + * them now. Otherwise free_used_maps() will release them. */ release_maps(env); *prog = env->prog; -- cgit v1.2.3 From 2dde48178ba5e66a2ac7235eaebad5655ae6db3e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ondrej=20Mosn=C3=A1=C4=8Dek?= Date: Mon, 9 Apr 2018 10:00:06 +0200 Subject: audit: allow not equal op for audit by executable [ Upstream commit 23bcc480dac204c7dbdf49d96b2c918ed98223c2 ] Current implementation of auditing by executable name only implements the 'equal' operator. This patch extends it to also support the 'not equal' operator. See: https://github.com/linux-audit/audit-kernel/issues/53 Signed-off-by: Ondrej Mosnacek Reviewed-by: Richard Guy Briggs Signed-off-by: Paul Moore Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/auditfilter.c | 2 +- kernel/auditsc.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index b8ff9e193753..b57f929f1b46 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -406,7 +406,7 @@ static int audit_field_valid(struct audit_entry *entry, struct audit_field *f) return -EINVAL; break; case AUDIT_EXE: - if (f->op != Audit_equal) + if (f->op != Audit_not_equal && f->op != Audit_equal) return -EINVAL; if (entry->rule.listnr != AUDIT_FILTER_EXIT) return -EINVAL; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 7444f95f3ee9..0fe8b337291a 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -470,6 +470,8 @@ static int audit_filter_rules(struct task_struct *tsk, break; case AUDIT_EXE: result = audit_exe_compare(tsk, rule->exe); + if (f->op == Audit_not_equal) + result = !result; break; case AUDIT_UID: result = audit_uid_comparator(cred->uid, f->op, f->uid); -- cgit v1.2.3