On Tue, Apr 09, 2024 at 10:10:37AM +0800, George Guo wrote:
> From: George Guo <guodongtai@xxxxxxxxxx>
No, you are not the author of this :(
> commit 912201345f7c39e6b0ac283207be2b6641fa47b9 upstream.
>
> The destroy_synth_var_refs() destroyed hist_data, casusing a double-free
> error flagged by KASAN.
>
> This is tested via "./ftracetest test.d/trigger/inter-event/
> trigger-field-variable-support.tc"
>
> ==================================================================
> BUG: KASAN: use-after-free in destroy_hist_field+0x115/0x140
> Read of size 4 at addr ffff888012e95318 by task ftracetest/1858
>
> CPU: 1 PID: 1858 Comm: ftracetest Kdump: loaded Tainted: GE 4.19.90-89 #24
> Source Version: Unknown
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0
> Call Trace:
> dump_stack+0xcb/0x10b
> print_address_description.cold+0x54/0x249
> kasan_report_error.cold+0x63/0xab
> ? destroy_hist_field+0x115/0x140
> __asan_report_load4_noabort+0x8d/0xa0
> ? destroy_hist_field+0x115/0x140
> destroy_hist_field+0x115/0x140
> destroy_hist_data+0x4e4/0x9a0
> event_hist_trigger_free+0x212/0x2f0
> ? update_cond_flag+0x128/0x170
> ? event_hist_trigger_func+0x2880/0x2880
> hist_unregister_trigger+0x2f2/0x4f0
> event_hist_trigger_func+0x168c/0x2880
> ? tracing_map_read_var_once+0xd0/0xd0
> ? create_key_field+0x520/0x520
> ? __mutex_lock_slowpath+0x10/0x10
> event_trigger_write+0x2f4/0x490
> ? trigger_start+0x180/0x180
> ? __fget_light+0x369/0x5d0
> ? count_memcg_event_mm+0x104/0x2b0
> ? trigger_start+0x180/0x180
> __vfs_write+0x81/0x100
> vfs_write+0x1e1/0x540
> ksys_write+0x12a/0x290
> ? __ia32_sys_read+0xb0/0xb0
> ? __close_fd+0x1d3/0x280
> do_syscall_64+0xe3/0x2d0
> entry_SYSCALL_64_after_hwframe+0x5c/0xc1
> RIP: 0033:0x7efdd342ee04
> Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f 80 00 00 00 00 48
> 8d 05 39 34 0c 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff
> ff 77 54 f3 c3 66 90 41 54 55 49 89 d4 53 48 89 f5
> RSP: 002b:00007ffda01f5e08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 00000000000000b4 RCX: 00007efdd342ee04
> RDX: 00000000000000b4 RSI: 000055c5b41b1e90 RDI: 0000000000000001
> RBP: 000055c5b41b1e90 R08: 000000000000000a R09: 0000000000000000
> R10: 000000000000000a R11: 0000000000000246 R12: 00007efdd34ed5c0
> R13: 00000000000000b4 R14: 00007efdd34ed7c0 R15: 00000000000000b4
> ==================================================================
>
> So remove the destroy_synth_var_refs() call for that hist_data.
That is not the commit log for the referenced commit.
>
> Fixes: c282a386a397 ("tracing: Add 'onmatch' hist trigger action support")
> Signed-off-by: George Guo <guodongtai@xxxxxxxxxx>
And you dropped all of the people on the original commit :(
Please fix all of this up if you wish to have these backports applied.
thanks,
greg k-h
