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| author | Ming Lei <ming.lei@canonical.com> | 2013-04-04 16:22:37 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-04-06 00:35:52 +0200 |
| commit | bb2b0051d7b0772ea9d0b4be900c2d965093f5d7 (patch) | |
| tree | ea77b283a68b2b2a5cbcf29706d8c2d6361d18e6 /block/genhd.c | |
| parent | sysfs: fix crash_notes_size build warning (diff) | |
| download | linux-bb2b0051d7b0772ea9d0b4be900c2d965093f5d7.tar.xz linux-bb2b0051d7b0772ea9d0b4be900c2d965093f5d7.zip | |
sysfs: check if one entry has been removed before freeing
It might be a kernel disaster if one sysfs entry is freed but
still referenced by sysfs tree.
Recently Dave and Sasha reported one use-after-free problem on
sysfs entry, and the problem has been troubleshooted with help
of debug message added in this patch.
Given sysfs_get_dirent/sysfs_put are exported APIs, even inside
sysfs they are called in many contexts(kobject/attribe add/delete,
inode init/drop, dentry lookup/release, readdir, ...), it is healthful
to check the removed flag before freeing one entry and dump message
if it is freeing without being removed first.
Cc: Dave Jones <davej@redhat.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block/genhd.c')
0 files changed, 0 insertions, 0 deletions