Commit 2928f0d0 authored by Adam Thomas's avatar Adam Thomas Committed by Artem Bityutskiy
Browse files

UBIFS: fix use of freed ubifs_orphan objects 



The last orphan in the cnext list has its cnext set to NULL. Because
of that, ubifs_delete_orphan assumes that it is not on the cnext list
and frees it immediately instead of adding it to the dnext list. The
freed orphan is later modified by write_orph_node.

This can cause various inconsistencies including directory entries
that cannot be removed and this error:

UBIFS error (pid 20685): layout_cnodes: LPT out of space at LEB 14:129009 needing 17, done_ltab 1, done_lsave 1

This is a regression introduced by
"7074e5eb UBIFS: remove invalid reference to list iterator variable".

This change adds an explicit flag to ubifs_orphan indicating whether
it is pending commit.

Signed-off-by: default avatarAdam Thomas <adamthomas1111@gmail.com>
Reviewed-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org # v3.6+
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
parent 3d251a5b

fs/ubifs/orphan.c

+6 −1
Original line number Diff line number Diff line
@@ -132,7 +132,7 @@ void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum) 
					(unsigned long)inum);

				return;

			}

			if (o->cnext) {

			if (o->cmt) {

				o->dnext = c->orph_dnext;

				c->orph_dnext = o;

				spin_unlock(&c->orphan_lock);
@@ -172,7 +172,9 @@ int ubifs_orphan_start_commit(struct ubifs_info *c) 
	last = &c->orph_cnext;

	list_for_each_entry(orphan, &c->orph_new, new_list) {

		ubifs_assert(orphan->new);

		ubifs_assert(!orphan->cmt);

		orphan->new = 0;

		orphan->cmt = 1;

		*last = orphan;

		last = &orphan->cnext;

	}
@@ -299,7 +301,9 @@ static int write_orph_node(struct ubifs_info *c, int atomic) 
	cnext = c->orph_cnext;

	for (i = 0; i < cnt; i++) {

		orphan = cnext;

		ubifs_assert(orphan->cmt);

		orph->inos[i] = cpu_to_le64(orphan->inum);

		orphan->cmt = 0;

		cnext = orphan->cnext;

		orphan->cnext = NULL;

	}
@@ -378,6 +382,7 @@ static int consolidate(struct ubifs_info *c) 
		list_for_each_entry(orphan, &c->orph_list, list) {

			if (orphan->new)

				continue;

			orphan->cmt = 1;

			*last = orphan;

			last = &orphan->cnext;

			cnt += 1;

fs/ubifs/ubifs.h

+3 −1
Original line number Diff line number Diff line
@@ -904,6 +904,7 @@ struct ubifs_budget_req { 
 * @dnext: next orphan to delete

 * @inum: inode number

 * @new: %1 => added since the last commit, otherwise %0

 * @cmt: %1 => commit pending, otherwise %0

 */

struct ubifs_orphan {

	struct rb_node rb;
@@ -912,7 +913,8 @@ struct ubifs_orphan { 
	struct ubifs_orphan *cnext;

	struct ubifs_orphan *dnext;

	ino_t inum;

	int new;

	unsigned new:1;

	unsigned cmt:1;

};



/**

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