From 28c4d9bc0708956c1a736a9e49fee71b65deee81 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Wed, 6 Aug 2025 23:34:03 +0200 Subject: [PATCH] gfs2: Fix unlikely race in gdlm_put_lock In gdlm_put_lock(), there is a small window of time in which the DFL_UNMOUNT flag has been set but the lockspace hasn't been released, yet. In that window, dlm may still call gdlm_ast() and gdlm_bast(). To prevent it from dereferencing freed glock objects, only free the glock if the lockspace has actually been released. Signed-off-by: Andreas Gruenbacher Reviewed-by: Andrew Price --- fs/gfs2/lock_dlm.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c index 3c7db20ce5642..ae058b1f9435d 100644 --- a/fs/gfs2/lock_dlm.c +++ b/fs/gfs2/lock_dlm.c @@ -344,12 +344,6 @@ static void gdlm_put_lock(struct gfs2_glock *gl) gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT); gfs2_update_request_times(gl); - /* don't want to call dlm if we've unmounted the lock protocol */ - if (test_bit(DFL_UNMOUNT, &ls->ls_recover_flags)) { - gfs2_glock_free(gl); - return; - } - /* * When the lockspace is released, all remaining glocks will be * unlocked automatically. This is more efficient than unlocking them @@ -379,6 +373,11 @@ again: goto again; } + if (error == -ENODEV) { + gfs2_glock_free(gl); + return; + } + if (error) { fs_err(sdp, "gdlm_unlock %x,%llx err=%d\n", gl->gl_name.ln_type, -- 2.47.3