From bb6cc253861bd5a7cf8439e2118659696df9619f Mon Sep 17 00:00:00 2001
From: Markus Weippert <markus@gekmihesg.de>
Date: Fri, 24 Nov 2023 16:14:37 +0100
Subject: [PATCH] bcache: revert replacing IS_ERR_OR_NULL with IS_ERR
Git-commit: bb6cc253861bd5a7cf8439e2118659696df9619f
Patch-mainline: v6.7-rc4
References: git-fixes
Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in
node allocations") replaced IS_ERR_OR_NULL by IS_ERR. This leads to a
NULL pointer dereference.
Bug: kernel NULL pointer dereference, address: 0000000000000080
Call Trace:
? __die_body.cold+0x1a/0x1f
? page_fault_oops+0xd2/0x2b0
? exc_page_fault+0x70/0x170
? asm_exc_page_fault+0x22/0x30
? btree_node_free+0xf/0x160 [bcache]
? up_write+0x32/0x60
btree_gc_coalesce+0x2aa/0x890 [bcache]
? bch_extent_bad+0x70/0x170 [bcache]
btree_gc_recurse+0x130/0x390 [bcache]
? btree_gc_mark_node+0x72/0x230 [bcache]
bch_btree_gc+0x5da/0x600 [bcache]
? cpuusage_read+0x10/0x10
? bch_btree_gc+0x600/0x600 [bcache]
bch_gc_thread+0x135/0x180 [bcache]
The relevant code starts with:
new_nodes[0] = NULL;
for (i = 0; i < nodes; i++) {
if (__bch_keylist_realloc(&keylist, bkey_u64s(&r[i].b->key)))
goto out_nocoalesce;
// ...
Out_nocoalesce: // ...
for (i = 0; i < nodes; i++)
if (!IS_ERR(new_nodes[i])) { // IS_ERR_OR_NULL before
028ddcac477b
btree_node_free(new_nodes[i]); // new_nodes[0] is NULL
rw_unlock(true, new_nodes[i]);
}
This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this.
Fixes: 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations")
Link: https://lore.kernel.org/all/3DF4A87A-2AC1-4893-AE5F-E921478419A9@suse.de/
Cc: stable@vger.kernel.org
Cc: Zheng Wang <zyytlz.wz@163.com>
Cc: Coly Li <colyli@suse.de>
Signed-off-by: Markus Weippert <markus@gekmihesg.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/bcache/btree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index de3019972b35..261596791218 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1522,7 +1522,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
bch_keylist_free(&keylist);
for (i = 0; i < nodes; i++)
- if (!IS_ERR(new_nodes[i])) {
+ if (!IS_ERR_OR_NULL(new_nodes[i])) {
btree_node_free(new_nodes[i]);
rw_unlock(true, new_nodes[i]);
}
--
2.35.3