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Commit | Line | Data |
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452f9198 GKH |
1 | From f01098c74b5219f3969d4750eeed1a36bfc038e3 Mon Sep 17 00:00:00 2001 |
2 | From: Eiichi Tsukata <devel@etsukata.com> | |
3 | Date: Fri, 14 Jun 2019 16:40:25 +0900 | |
4 | Subject: tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create() | |
5 | ||
6 | From: Eiichi Tsukata <devel@etsukata.com> | |
7 | ||
8 | commit f01098c74b5219f3969d4750eeed1a36bfc038e3 upstream. | |
9 | ||
10 | Just like the case of commit 8b05a3a7503c ("tracing/kprobes: Fix NULL | |
11 | pointer dereference in trace_kprobe_create()"), writing an incorrectly | |
12 | formatted string to uprobe_events can trigger NULL pointer dereference. | |
13 | ||
14 | Reporeducer: | |
15 | ||
16 | # echo r > /sys/kernel/debug/tracing/uprobe_events | |
17 | ||
18 | dmesg: | |
19 | ||
20 | BUG: kernel NULL pointer dereference, address: 0000000000000000 | |
21 | #PF: supervisor read access in kernel mode | |
22 | #PF: error_code(0x0000) - not-present page | |
23 | PGD 8000000079d12067 P4D 8000000079d12067 PUD 7b7ab067 PMD 0 | |
24 | Oops: 0000 [#1] PREEMPT SMP PTI | |
25 | CPU: 0 PID: 1903 Comm: bash Not tainted 5.2.0-rc3+ #15 | |
26 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014 | |
27 | RIP: 0010:strchr+0x0/0x30 | |
28 | Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 84 00 00 00 00 00 <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c | |
29 | RSP: 0018:ffffb55fc0403d10 EFLAGS: 00010293 | |
30 | ||
31 | RAX: ffff993ffb793400 RBX: 0000000000000000 RCX: ffffffffa4852625 | |
32 | RDX: 0000000000000000 RSI: 000000000000002f RDI: 0000000000000000 | |
33 | RBP: ffffb55fc0403dd0 R08: ffff993ffb793400 R09: 0000000000000000 | |
34 | R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 | |
35 | R13: ffff993ff9cc1668 R14: 0000000000000001 R15: 0000000000000000 | |
36 | FS: 00007f30c5147700(0000) GS:ffff993ffda00000(0000) knlGS:0000000000000000 | |
37 | CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 | |
38 | CR2: 0000000000000000 CR3: 000000007b628000 CR4: 00000000000006f0 | |
39 | Call Trace: | |
40 | trace_uprobe_create+0xe6/0xb10 | |
41 | ? __kmalloc_track_caller+0xe6/0x1c0 | |
42 | ? __kmalloc+0xf0/0x1d0 | |
43 | ? trace_uprobe_create+0xb10/0xb10 | |
44 | create_or_delete_trace_uprobe+0x35/0x90 | |
45 | ? trace_uprobe_create+0xb10/0xb10 | |
46 | trace_run_command+0x9c/0xb0 | |
47 | trace_parse_run_command+0xf9/0x1eb | |
48 | ? probes_open+0x80/0x80 | |
49 | __vfs_write+0x43/0x90 | |
50 | vfs_write+0x14a/0x2a0 | |
51 | ksys_write+0xa2/0x170 | |
52 | do_syscall_64+0x7f/0x200 | |
53 | entry_SYSCALL_64_after_hwframe+0x49/0xbe | |
54 | ||
55 | Link: http://lkml.kernel.org/r/20190614074026.8045-1-devel@etsukata.com | |
56 | ||
57 | Cc: stable@vger.kernel.org | |
58 | Fixes: 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for uprobe events") | |
59 | Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> | |
60 | Signed-off-by: Eiichi Tsukata <devel@etsukata.com> | |
61 | Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> | |
62 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
63 | ||
64 | --- | |
65 | kernel/trace/trace_uprobe.c | 13 ++++++++++--- | |
66 | 1 file changed, 10 insertions(+), 3 deletions(-) | |
67 | ||
68 | --- a/kernel/trace/trace_uprobe.c | |
69 | +++ b/kernel/trace/trace_uprobe.c | |
70 | @@ -434,10 +434,17 @@ static int trace_uprobe_create(int argc, | |
71 | ret = 0; | |
72 | ref_ctr_offset = 0; | |
73 | ||
74 | - /* argc must be >= 1 */ | |
75 | - if (argv[0][0] == 'r') | |
76 | + switch (argv[0][0]) { | |
77 | + case 'r': | |
78 | is_return = true; | |
79 | - else if (argv[0][0] != 'p' || argc < 2) | |
80 | + break; | |
81 | + case 'p': | |
82 | + break; | |
83 | + default: | |
84 | + return -ECANCELED; | |
85 | + } | |
86 | + | |
87 | + if (argc < 2) | |
88 | return -ECANCELED; | |
89 | ||
90 | if (argv[0][1] == ':') |