Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-22 12:11:40 +00:00
Code Issues Packages Projects Releases Wiki Activity

tracing: Fix uaf issue when open the hist or hist_debug file

Browse Source 
KASAN report following issue. The root cause is when opening 'hist'
file of an instance and accessing 'trace_event_file' in hist_show(),
but 'trace_event_file' has been freed due to the instance being removed.
'hist_debug' file has the same problem. To fix it, call
tracing_{open,release}_file_tr() in file_operations callback to have
the ref count and avoid 'trace_event_file' being freed.

  BUG: KASAN: slab-use-after-free in hist_show+0x11e0/0x1278
  Read of size 8 at addr ffff242541e336b8 by task head/190

  CPU: 4 PID: 190 Comm: head Not tainted 6.7.0-rc5-g26aff849438c #133
  Hardware name: linux,dummy-virt (DT)
  Call trace:
   dump_backtrace+0x98/0xf8
   show_stack+0x1c/0x30
   dump_stack_lvl+0x44/0x58
   print_report+0xf0/0x5a0
   kasan_report+0x80/0xc0
   __asan_report_load8_noabort+0x1c/0x28
   hist_show+0x11e0/0x1278
   seq_read_iter+0x344/0xd78
   seq_read+0x128/0x1c0
   vfs_read+0x198/0x6c8
   ksys_read+0xf4/0x1e0
   __arm64_sys_read+0x70/0xa8
   invoke_syscall+0x70/0x260
   el0_svc_common.constprop.0+0xb0/0x280
   do_el0_svc+0x44/0x60
   el0_svc+0x34/0x68
   el0t_64_sync_handler+0xb8/0xc0
   el0t_64_sync+0x168/0x170

  Allocated by task 188:
   kasan_save_stack+0x28/0x50
   kasan_set_track+0x28/0x38
   kasan_save_alloc_info+0x20/0x30
   __kasan_slab_alloc+0x6c/0x80
   kmem_cache_alloc+0x15c/0x4a8
   trace_create_new_event+0x84/0x348
   __trace_add_new_event+0x18/0x88
   event_trace_add_tracer+0xc4/0x1a0
   trace_array_create_dir+0x6c/0x100
   trace_array_create+0x2e8/0x568
   instance_mkdir+0x48/0x80
   tracefs_syscall_mkdir+0x90/0xe8
   vfs_mkdir+0x3c4/0x610
   do_mkdirat+0x144/0x200
   __arm64_sys_mkdirat+0x8c/0xc0
   invoke_syscall+0x70/0x260
   el0_svc_common.constprop.0+0xb0/0x280
   do_el0_svc+0x44/0x60
   el0_svc+0x34/0x68
   el0t_64_sync_handler+0xb8/0xc0
   el0t_64_sync+0x168/0x170

  Freed by task 191:
   kasan_save_stack+0x28/0x50
   kasan_set_track+0x28/0x38
   kasan_save_free_info+0x34/0x58
   __kasan_slab_free+0xe4/0x158
   kmem_cache_free+0x19c/0x508
   event_file_put+0xa0/0x120
   remove_event_file_dir+0x180/0x320
   event_trace_del_tracer+0xb0/0x180
   __remove_instance+0x224/0x508
   instance_rmdir+0x44/0x78
   tracefs_syscall_rmdir+0xbc/0x140
   vfs_rmdir+0x1cc/0x4c8
   do_rmdir+0x220/0x2b8
   __arm64_sys_unlinkat+0xc0/0x100
   invoke_syscall+0x70/0x260
   el0_svc_common.constprop.0+0xb0/0x280
   do_el0_svc+0x44/0x60
   el0_svc+0x34/0x68
   el0t_64_sync_handler+0xb8/0xc0
   el0t_64_sync+0x168/0x170

Link: https://lore.kernel.org/linux-trace-kernel/20231214012153.676155-1-zhengyejian1@huawei.com

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Zheng Yejian 2023-12-14 09:21:53 +08:00 committed by Steven Rostedt (Google)
parent 60be76eeab
commit 1cc111b9cd
3 changed files with 15 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
kernel/trace/trace.c
View File

@ -4968,6 +4968,12 @@ int tracing_release_file_tr(struct inode *inode, struct file *filp)
return 0;
}
int tracing_single_release_file_tr(struct inode *inode, struct file *filp)
{
tracing_release_file_tr(inode, filp);
return single_release(inode, filp);
}
static int tracing_mark_open(struct inode *inode, struct file *filp)
{
stream_open(inode, filp);

1
kernel/trace/trace.h
View File

@ -617,6 +617,7 @@ int tracing_open_generic(struct inode *inode, struct file *filp);
int tracing_open_generic_tr(struct inode *inode, struct file *filp);
int tracing_open_file_tr(struct inode *inode, struct file *filp);
int tracing_release_file_tr(struct inode *inode, struct file *filp);
int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
bool tracing_is_disabled(void);
bool tracer_tracing_is_on(struct trace_array *tr);
void tracer_tracing_on(struct trace_array *tr);

12
kernel/trace/trace_events_hist.c
View File

@ -5623,10 +5623,12 @@ static int event_hist_open(struct inode *inode, struct file *file)
{
int ret;
ret = security_locked_down(LOCKDOWN_TRACEFS);
ret = tracing_open_file_tr(inode, file);
if (ret)
return ret;
/* Clear private_data to avoid warning in single_open() */
file->private_data = NULL;
return single_open(file, hist_show, file);
}
@ -5634,7 +5636,7 @@ const struct file_operations event_hist_fops = {
.open = event_hist_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.release = tracing_single_release_file_tr,
};
#ifdef CONFIG_HIST_TRIGGERS_DEBUG
@ -5900,10 +5902,12 @@ static int event_hist_debug_open(struct inode *inode, struct file *file)
{
int ret;
ret = security_locked_down(LOCKDOWN_TRACEFS);
ret = tracing_open_file_tr(inode, file);
if (ret)
return ret;
/* Clear private_data to avoid warning in single_open() */
file->private_data = NULL;
return single_open(file, hist_debug_show, file);
}
@ -5911,7 +5915,7 @@ const struct file_operations event_hist_debug_fops = {
.open = event_hist_debug_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.release = tracing_single_release_file_tr,
};
#endif