From: Rafał Miłecki <rafal@xxxxxxxxxx>
This fixes unbalanced of_node_put():
[ 1.078910] 6 cmdlinepart partitions found on MTD device gpmi-nand
[ 1.085116] Creating 6 MTD partitions on "gpmi-nand":
[ 1.090181] 0x000000000000-0x000008000000 : "nandboot"
[ 1.096952] 0x000008000000-0x000009000000 : "nandfit"
[ 1.103547] 0x000009000000-0x00000b000000 : "nandkernel"
[ 1.110317] 0x00000b000000-0x00000c000000 : "nanddtb"
[ 1.115525] ------------[ cut here ]------------
[ 1.120141] refcount_t: addition on 0; use-after-free.
[ 1.125328] WARNING: CPU: 0 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0xdc/0x148
[ 1.133528] Modules linked in:
[ 1.136589] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.0.0-rc7-next-20220930-04543-g8cf3f7
[ 1.146342] Hardware name: Freescale i.MX8DXL DDR3L EVK (DT)
[ 1.151999] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 1.158965] pc : refcount_warn_saturate+0xdc/0x148
[ 1.163760] lr : refcount_warn_saturate+0xdc/0x148
[ 1.168556] sp : ffff800009ddb080
[ 1.171866] x29: ffff800009ddb080 x28: ffff800009ddb35a x27: 0000000000000002
[ 1.179015] x26: ffff8000098b06ad x25: ffffffffffffffff x24: ffff0a00ffffff05
[ 1.186165] x23: ffff00001fdf6470 x22: ffff800009ddb367 x21: 0000000000000000
[ 1.193314] x20: ffff00001fdfebe8 x19: ffff00001fdfec50 x18: ffffffffffffffff
[ 1.200464] x17: 0000000000000000 x16: 0000000000000118 x15: 0000000000000004
[ 1.207614] x14: 0000000000000fff x13: ffff800009bca248 x12: 0000000000000003
[ 1.214764] x11: 00000000ffffefff x10: c0000000ffffefff x9 : 4762cb2ccb52de00
[ 1.221914] x8 : 4762cb2ccb52de00 x7 : 205d313431303231 x6 : 312e31202020205b
[ 1.229063] x5 : ffff800009d55c1f x4 : 0000000000000001 x3 : 0000000000000000
[ 1.236213] x2 : 0000000000000000 x1 : ffff800009954be6 x0 : 000000000000002a
[ 1.243365] Call trace:
[ 1.245806] refcount_warn_saturate+0xdc/0x148
[ 1.250253] kobject_get+0x98/0x9c
[ 1.253658] of_node_get+0x20/0x34
[ 1.257072] of_fwnode_get+0x3c/0x54
[ 1.260652] fwnode_get_nth_parent+0xd8/0xf4
[ 1.264926] fwnode_full_name_string+0x3c/0xb4
[ 1.269373] device_node_string+0x498/0x5b4
[ 1.273561] pointer+0x41c/0x5d0
[ 1.276793] vsnprintf+0x4d8/0x694
[ 1.280198] vprintk_store+0x164/0x528
[ 1.283951] vprintk_emit+0x98/0x164
[ 1.287530] vprintk_default+0x44/0x6c
[ 1.291284] vprintk+0xf0/0x134
[ 1.294428] _printk+0x54/0x7c
[ 1.297486] of_node_release+0xe8/0x128
[ 1.301326] kobject_put+0x98/0xfc
[ 1.304732] of_node_put+0x1c/0x28
[ 1.308137] add_mtd_device+0x484/0x6d4
[ 1.311977] add_mtd_partitions+0xf0/0x1d0
[ 1.316078] parse_mtd_partitions+0x45c/0x518
[ 1.320439] mtd_device_parse_register+0xb0/0x274
[ 1.325147] gpmi_nand_probe+0x51c/0x650
[ 1.329074] platform_probe+0xa8/0xd0
[ 1.332740] really_probe+0x130/0x334
[ 1.336406] __driver_probe_device+0xb4/0xe0
[ 1.340681] driver_probe_device+0x3c/0x1f8
[ 1.344869] __driver_attach+0xdc/0x1a4
[ 1.348708] bus_for_each_dev+0x80/0xcc
[ 1.352548] driver_attach+0x24/0x30
[ 1.356127] bus_add_driver+0x108/0x1f4
[ 1.359967] driver_register+0x78/0x114
[ 1.363807] __platform_driver_register+0x24/0x30
[ 1.368515] gpmi_nand_driver_init+0x1c/0x28
[ 1.372798] do_one_initcall+0xbc/0x238
[ 1.376638] do_initcall_level+0x94/0xb4
[ 1.380565] do_initcalls+0x54/0x94
[ 1.384058] do_basic_setup+0x1c/0x28
[ 1.387724] kernel_init_freeable+0x110/0x188
[ 1.392084] kernel_init+0x20/0x1a0
[ 1.395578] ret_from_fork+0x10/0x20
[ 1.399157] ---[ end trace 0000000000000000 ]---
[ 1.403782] ------------[ cut here ]------------
Reported-by: Han Xu <han.xu@xxxxxxx>
Fixes: ad9b10d1eaada169 ("mtd: core: introduce of support for dynamic partitions")
Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
Tested-by: Han Xu <han.xu@xxxxxxx>
---
drivers/mtd/mtdcore.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 18aa54460d36..0b4ca0aa4132 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -562,7 +562,7 @@ static void mtd_check_of_node(struct mtd_info *mtd)
if (!mtd_is_partition(mtd))
return;
parent = mtd->parent;
- parent_dn = dev_of_node(&parent->dev);
+ parent_dn = of_node_get(dev_of_node(&parent->dev));
if (!parent_dn)
return;
--
2.34.1
