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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2014-01-02 11:52:20 +0100 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2014-01-02 13:18:04 +0100 |
| commit | 0b3a2c9968d453d5827e635a6f3d69129f70af66 (patch) | |
| tree | b5c0d6cee7f88e7d6dfc99afc51ec2be066906a8 /fs/gfs2/glock.c | |
| parent | GFS2: Wait for async DIO in glock state changes (diff) | |
| download | linux-0b3a2c9968d453d5827e635a6f3d69129f70af66.tar.xz linux-0b3a2c9968d453d5827e635a6f3d69129f70af66.zip | |
GFS2: Fix unsafe dereference in dump_holder()
GLOCK_BUG_ON() might call this function without RCU read lock. Make sure that
RCU read lock is held when using task_struct returned from pid_task().
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/glock.c')
| -rw-r--r-- | fs/gfs2/glock.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index c8420f7e4db6..6f7a47c05259 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -1655,6 +1655,7 @@ static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) struct task_struct *gh_owner = NULL; char flags_buf[32]; + rcu_read_lock(); if (gh->gh_owner_pid) gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %pS\n", @@ -1664,6 +1665,7 @@ static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, gh_owner ? gh_owner->comm : "(ended)", (void *)gh->gh_ip); + rcu_read_unlock(); return 0; } |