The patch titled Subject: ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3 has been added to the -mm tree. Its filename is ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: jiangyiwen <jiangyiwen@xxxxxxxxxx> Subject: ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3 The following case will lead to a lockres is freed but is still in use. cat /sys/kernel/debug/o2dlm/locking_state dlm_thread lockres_seq_start -> lock dlm->track_lock -> get resA resA->refs decrease to 0, call dlm_lockres_release, and wait for "cat" unlock. Although resA->refs is already set to 0, increase resA->refs, and then unlock lock dlm->track_lock -> list_del_init() -> unlock -> free resA In such a race case, invalid address access may occurs. So we should delete list res->tracking before resA->refs decrease to 0. Signed-off-by: Yiwen Jiang <jiangyiwen@xxxxxxxxxx> Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Mark Fasheh <mfasheh@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ocfs2/dlm/dlmmaster.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff -puN fs/ocfs2/dlm/dlmmaster.c~ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3 fs/ocfs2/dlm/dlmmaster.c --- a/fs/ocfs2/dlm/dlmmaster.c~ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3 +++ a/fs/ocfs2/dlm/dlmmaster.c @@ -772,8 +772,19 @@ lookup: dlm_lockres_grab_inflight_ref(dlm, tmpres); spin_unlock(&tmpres->spinlock); - if (res) + if (res) { + spin_lock(&dlm->track_lock); + if (!list_empty(&res->tracking)) + list_del_init(&res->tracking); + else { + mlog(ML_ERROR, "Resource %.*s not " + "on the Tracking list\n", + res->lockname.len, + res->lockname.name); + } + spin_unlock(&dlm->track_lock); dlm_lockres_put(res); + } res = tmpres; goto leave; } _ Patches currently in -mm which might be from jiangyiwen@xxxxxxxxxx are ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages.patch ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html