diff options
author | Song Liu <songliubraving@fb.com> | 2018-04-23 10:21:34 -0700 |
---|---|---|
committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-04-26 14:49:55 -0400 |
commit | 0c92c7a3c5d416f47b32c5f20a611dfeca5d5f2e (patch) | |
tree | c026dee7fb9670fd19974890fa441085912299cd /kernel/events | |
parent | 9a0fd675304d410f3a9586e1b333e16f4658d56c (diff) |
tracing: Fix bad use of igrab in trace_uprobe.c
As Miklos reported and suggested:
This pattern repeats two times in trace_uprobe.c and in
kernel/events/core.c as well:
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret)
goto fail_address_parse;
inode = igrab(d_inode(path.dentry));
path_put(&path);
And it's wrong. You can only hold a reference to the inode if you
have an active ref to the superblock as well (which is normally
through path.mnt) or holding s_umount.
This way unmounting the containing filesystem while the tracepoint is
active will give you the "VFS: Busy inodes after unmount..." message
and a crash when the inode is finally put.
Solution: store path instead of inode.
This patch fixes two instances in trace_uprobe.c. struct path is added to
struct trace_uprobe to keep the inode and containing mount point
referenced.
Link: http://lkml.kernel.org/r/20180423172135.4050588-1-songliubraving@fb.com
Fixes: f3f096cfedf8 ("tracing: Provide trace events interface for uprobes")
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Howard McLauchlan <hmclauchlan@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/events')
0 files changed, 0 insertions, 0 deletions