linux-stable.git/drivers/mtd/mtdcore.c, branch linux-6.2.y Linux kernel stable tree mtd: core: fix error path for nvmem provider 2023-05-11T14:11:33+00:00 Michael Walle michael@walle.cc 2023-03-08T08:20:20+00:00 949476b8601bde5459048eebdf457c9db20addd8 commit e0489f6e221f5ddee6cb3bd51b992b790c5fa4b9 upstream. If mtd_otp_nvmem_add() fails, the partitions won't be removed because there is simply no call to del_mtd_partitions(). Unfortunately, add_mtd_partitions() will print all partitions to the kernel console. If mtd_otp_nvmem_add() returns -EPROBE_DEFER this would print the partitions multiple times to the kernel console. Instead move mtd_otp_nvmem_add() to the beginning of the function. Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support") Cc: stable@vger.kernel.org Signed-off-by: Michael Walle <michael@walle.cc> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-3-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e0489f6e221f5ddee6cb3bd51b992b790c5fa4b9 upstream.

If mtd_otp_nvmem_add() fails, the partitions won't be removed
because there is simply no call to del_mtd_partitions().
Unfortunately, add_mtd_partitions() will print all partitions to
the kernel console. If mtd_otp_nvmem_add() returns -EPROBE_DEFER
this would print the partitions multiple times to the kernel
console. Instead move mtd_otp_nvmem_add() to the beginning of the
function.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-3-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mtd: core: fix nvmem error reporting 2023-05-11T14:11:33+00:00 Michael Walle michael@walle.cc 2023-03-08T08:20:19+00:00 249858575fd3f27904d6bb775e5ab500e9ef3b0f commit 8bd1d24e6ca3c599dd455b0e1b22f77bab8290eb upstream. The master MTD will only have an associated device if CONFIG_MTD_PARTITIONED_MASTER is set, thus we cannot use dev_err() on mtd->dev. Instead use the parent device which is the physical flash memory. Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support") Cc: stable@vger.kernel.org Signed-off-by: Michael Walle <michael@walle.cc> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-2-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8bd1d24e6ca3c599dd455b0e1b22f77bab8290eb upstream.

The master MTD will only have an associated device if
CONFIG_MTD_PARTITIONED_MASTER is set, thus we cannot use dev_err() on
mtd->dev. Instead use the parent device which is the physical flash
memory.

Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-2-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mtd: core: provide unique name for nvmem device, take two 2023-05-11T14:11:33+00:00 Michael Walle michael@walle.cc 2023-03-08T08:20:18+00:00 2321e93413848e7924454677dc9217d66d3e790b commit 1cd9ceaa5282ff10ea20a7fbadde5a476a1cc99e upstream. Commit c048b60d39e1 ("mtd: core: provide unique name for nvmem device") tries to give the nvmem device a unique name, but fails badly if the mtd device doesn't have a "struct device" associated with it, i.e. if CONFIG_MTD_PARTITIONED_MASTER is not set. This will result in the name "(null)-user-otp", which is not unique. It seems the best we can do is to use the compatible name together with a unique identifier added by the nvmem subsystem by using NVMEM_DEVID_AUTO. Fixes: c048b60d39e1 ("mtd: core: provide unique name for nvmem device") Cc: stable@vger.kernel.org Signed-off-by: Michael Walle <michael@walle.cc> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-1-michael@walle.cc Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1cd9ceaa5282ff10ea20a7fbadde5a476a1cc99e upstream.

Commit c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
tries to give the nvmem device a unique name, but fails badly if the mtd
device doesn't have a "struct device" associated with it, i.e. if
CONFIG_MTD_PARTITIONED_MASTER is not set. This will result in the name
"(null)-user-otp", which is not unique. It seems the best we can do is
to use the compatible name together with a unique identifier added by
the nvmem subsystem by using NVMEM_DEVID_AUTO.

Fixes: c048b60d39e1 ("mtd: core: provide unique name for nvmem device")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230308082021.870459-1-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mtd: core: Fix refcount error in del_mtd_device() 2022-11-24T11:32:16+00:00 Shang XiaoJing shangxiaojing@huawei.com 2022-11-19T06:39:15+00:00 56570bdad5e31c5c538cd6efff5c4510256e1bb4 del_mtd_device() will call of_node_put() to mtd_get_of_node(mtd), which is mtd->dev.of_node. However, memset(&mtd->dev, 0) is called before of_node_put(). As the result, of_node_put() won't do anything in del_mtd_device(), and causes the refcount leak. del_mtd_device() memset(&mtd->dev, 0, sizeof(mtd->dev) # clear mtd->dev of_node_put() mtd_get_of_node(mtd) # mtd->dev is cleared, can't locate of_node # of_node_put(NULL) won't do anything Fix the error by caching the pointer of the device_node. OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /spi/spi-sram@0 CPU: 3 PID: 275 Comm: python3 Tainted: G N 6.1.0-rc3+ #54 0d8a1edddf51f172ff5226989a7565c6313b08e2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x67/0x83 kobject_get+0x155/0x160 of_node_get+0x1f/0x30 of_fwnode_get+0x43/0x70 fwnode_handle_get+0x54/0x80 fwnode_get_nth_parent+0xc9/0xe0 fwnode_full_name_string+0x3f/0xa0 device_node_string+0x30f/0x750 pointer+0x598/0x7a0 vsnprintf+0x62d/0x9b0 ... cfs_overlay_release+0x30/0x90 config_item_release+0xbe/0x1a0 config_item_put+0x5e/0x80 configfs_rmdir+0x3bd/0x540 vfs_rmdir+0x18c/0x320 do_rmdir+0x198/0x330 __x64_sys_rmdir+0x2c/0x40 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 00596576a051 ("mtd: core: clear out unregistered devices a bit more") Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> [<miquel.raynal@bootlin.com>: Light reword of the commit log] Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20221119063915.11108-1-shangxiaojing@huawei.com 
del_mtd_device() will call of_node_put() to mtd_get_of_node(mtd), which
is mtd->dev.of_node. However, memset(&mtd->dev, 0) is called before
of_node_put(). As the result, of_node_put() won't do anything in
del_mtd_device(), and causes the refcount leak.

del_mtd_device()
    memset(&mtd->dev, 0, sizeof(mtd->dev) # clear mtd->dev
    of_node_put()
        mtd_get_of_node(mtd) # mtd->dev is cleared, can't locate of_node
                             # of_node_put(NULL) won't do anything

Fix the error by caching the pointer of the device_node.

OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry: attach
overlay node /spi/spi-sram@0
CPU: 3 PID: 275 Comm: python3 Tainted: G N 6.1.0-rc3+ #54
    0d8a1edddf51f172ff5226989a7565c6313b08e2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
    dump_stack_lvl+0x67/0x83
    kobject_get+0x155/0x160
    of_node_get+0x1f/0x30
    of_fwnode_get+0x43/0x70
    fwnode_handle_get+0x54/0x80
    fwnode_get_nth_parent+0xc9/0xe0
    fwnode_full_name_string+0x3f/0xa0
    device_node_string+0x30f/0x750
    pointer+0x598/0x7a0
    vsnprintf+0x62d/0x9b0
    ...
    cfs_overlay_release+0x30/0x90
    config_item_release+0xbe/0x1a0
    config_item_put+0x5e/0x80
    configfs_rmdir+0x3bd/0x540
    vfs_rmdir+0x18c/0x320
    do_rmdir+0x198/0x330
    __x64_sys_rmdir+0x2c/0x40
    do_syscall_64+0x37/0x90
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 00596576a051 ("mtd: core: clear out unregistered devices a bit more")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
[<miquel.raynal@bootlin.com>: Light reword of the commit log]
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221119063915.11108-1-shangxiaojing@huawei.com
mtd: core: fix possible resource leak in init_mtd() 2022-11-07T16:14:20+00:00 Gaosheng Cui cuigaosheng1@huawei.com 2022-10-24T06:51:09+00:00 1aadf01e5076b9ab6bf294b9622335c651314895 I got the error report while inject fault in init_mtd(): sysfs: cannot create duplicate filename '/devices/virtual/bdi/mtd-0' Call Trace: <TASK> dump_stack_lvl+0x67/0x83 sysfs_warn_dup+0x60/0x70 sysfs_create_dir_ns+0x109/0x120 kobject_add_internal+0xce/0x2f0 kobject_add+0x98/0x110 device_add+0x179/0xc00 device_create_groups_vargs+0xf4/0x100 device_create+0x7b/0xb0 bdi_register_va.part.13+0x58/0x2d0 bdi_register+0x9b/0xb0 init_mtd+0x62/0x171 [mtd] do_one_initcall+0x6c/0x3c0 do_init_module+0x58/0x222 load_module+0x268e/0x27d0 __do_sys_finit_module+0xd5/0x140 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> kobject_add_internal failed for mtd-0 with -EEXIST, don't try to register things with the same name in the same directory. Error registering mtd class or bdi: -17 If init_mtdchar() fails in init_mtd(), mtd_bdi will not be unregistered, as a result, we can't load the mtd module again, to fix this by calling bdi_unregister(mtd_bdi) after out_procfs label. Fixes: 445caaa20c4d ("mtd: Allocate bdi objects dynamically") Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20221024065109.2050705-1-cuigaosheng1@huawei.com 
I got the error report while inject fault in init_mtd():

sysfs: cannot create duplicate filename '/devices/virtual/bdi/mtd-0'
Call Trace:
 <TASK>
 dump_stack_lvl+0x67/0x83
 sysfs_warn_dup+0x60/0x70
 sysfs_create_dir_ns+0x109/0x120
 kobject_add_internal+0xce/0x2f0
 kobject_add+0x98/0x110
 device_add+0x179/0xc00
 device_create_groups_vargs+0xf4/0x100
 device_create+0x7b/0xb0
 bdi_register_va.part.13+0x58/0x2d0
 bdi_register+0x9b/0xb0
 init_mtd+0x62/0x171 [mtd]
 do_one_initcall+0x6c/0x3c0
 do_init_module+0x58/0x222
 load_module+0x268e/0x27d0
 __do_sys_finit_module+0xd5/0x140
 do_syscall_64+0x37/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
 </TASK>
kobject_add_internal failed for mtd-0 with -EEXIST, don't try to register
	things with the same name in the same directory.
Error registering mtd class or bdi: -17

If init_mtdchar() fails in init_mtd(), mtd_bdi will not be unregistered,
as a result, we can't load the mtd module again, to fix this by calling
bdi_unregister(mtd_bdi) after out_procfs label.

Fixes: 445caaa20c4d ("mtd: Allocate bdi objects dynamically")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221024065109.2050705-1-cuigaosheng1@huawei.com
mtd: core: set ROOT_DEV for partitions marked as rootfs in DT 2022-11-07T16:14:18+00:00 Rafał Miłecki rafal@milecki.pl 2022-10-22T21:13:18+00:00 26422ac78e9d8767bd4aabfbae616b15edbf6a1b This adds support for "linux,rootfs" binding that is used to mark flash partition containing rootfs. It's useful for devices using device tree that don't have bootloader passing root info in cmdline. Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20221022211318.32009-2-zajec5@gmail.com 
This adds support for "linux,rootfs" binding that is used to mark flash
partition containing rootfs. It's useful for devices using device tree
that don't have bootloader passing root info in cmdline.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221022211318.32009-2-zajec5@gmail.com
mtd: Fix device name leak when register device failed in add_mtd_device() 2022-11-07T16:14:16+00:00 Zhang Xiaoxu zhangxiaoxu5@huawei.com 2022-10-22T12:13:52+00:00 895d68a39481a75c680aa421546931fb11942fa6 There is a kmemleak when register device failed: unreferenced object 0xffff888101aab550 (size 8): comm "insmod", pid 3922, jiffies 4295277753 (age 925.408s) hex dump (first 8 bytes): 6d 74 64 30 00 88 ff ff mtd0.... backtrace: [<00000000bde26724>] __kmalloc_node_track_caller+0x4e/0x150 [<000000003c32b416>] kvasprintf+0xb0/0x130 [<000000001f7a8f15>] kobject_set_name_vargs+0x2f/0xb0 [<000000006e781163>] dev_set_name+0xab/0xe0 [<00000000e30d0c78>] add_mtd_device+0x4bb/0x700 [<00000000f3d34de7>] mtd_device_parse_register+0x2ac/0x3f0 [<00000000c0d88488>] 0xffffffffa0238457 [<00000000b40d0922>] 0xffffffffa02a008f [<0000000023d17b9d>] do_one_initcall+0x87/0x2a0 [<00000000770f6ca6>] do_init_module+0xdf/0x320 [<000000007b6768fe>] load_module+0x2f98/0x3330 [<00000000346bed5a>] __do_sys_finit_module+0x113/0x1b0 [<00000000674c2290>] do_syscall_64+0x35/0x80 [<000000004c6a8d97>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 If register device failed, should call put_device() to give up the reference. Fixes: 1f24b5a8ecbb ("[MTD] driver model updates") Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20221022121352.2534682-1-zhangxiaoxu5@huawei.com 
There is a kmemleak when register device failed:
  unreferenced object 0xffff888101aab550 (size 8):
    comm "insmod", pid 3922, jiffies 4295277753 (age 925.408s)
    hex dump (first 8 bytes):
      6d 74 64 30 00 88 ff ff                          mtd0....
    backtrace:
      [<00000000bde26724>] __kmalloc_node_track_caller+0x4e/0x150
      [<000000003c32b416>] kvasprintf+0xb0/0x130
      [<000000001f7a8f15>] kobject_set_name_vargs+0x2f/0xb0
      [<000000006e781163>] dev_set_name+0xab/0xe0
      [<00000000e30d0c78>] add_mtd_device+0x4bb/0x700
      [<00000000f3d34de7>] mtd_device_parse_register+0x2ac/0x3f0
      [<00000000c0d88488>] 0xffffffffa0238457
      [<00000000b40d0922>] 0xffffffffa02a008f
      [<0000000023d17b9d>] do_one_initcall+0x87/0x2a0
      [<00000000770f6ca6>] do_init_module+0xdf/0x320
      [<000000007b6768fe>] load_module+0x2f98/0x3330
      [<00000000346bed5a>] __do_sys_finit_module+0x113/0x1b0
      [<00000000674c2290>] do_syscall_64+0x35/0x80
      [<000000004c6a8d97>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

If register device failed, should call put_device() to give up the
reference.

Fixes: 1f24b5a8ecbb ("[MTD] driver model updates")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221022121352.2534682-1-zhangxiaoxu5@huawei.com
mtd: core: try to find OF node for every MTD partition 2022-11-07T16:07:56+00:00 Rafał Miłecki rafal@milecki.pl 2022-10-04T08:37:10+00:00 2df11f00100d7278185a9dbefa20ba3f5d32401d So far this feature was limited to the top-level "nvmem-cells" node. There are multiple parsers creating partitions and subpartitions dynamically. Extend that code to handle them too. This allows finding partition-* node for every MTD (sub)partition. Random example: partitions { compatible = "brcm,bcm947xx-cfe-partitions"; partition-firmware { compatible = "brcm,trx"; partition-loader { }; }; }; Cc: Christian Marangi <ansuelsmth@gmail.com> Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-2-zajec5@gmail.com 
So far this feature was limited to the top-level "nvmem-cells" node.
There are multiple parsers creating partitions and subpartitions
dynamically. Extend that code to handle them too.

This allows finding partition-* node for every MTD (sub)partition.

Random example:

partitions {
	compatible = "brcm,bcm947xx-cfe-partitions";

	partition-firmware {
		compatible = "brcm,trx";

		partition-loader {
		};
	};
};

Cc: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-2-zajec5@gmail.com
mtd: core: simplify (a bit) code find partition-matching dynamic OF node 2022-11-07T16:06:30+00:00 Rafał Miłecki rafal@milecki.pl 2022-10-04T08:37:09+00:00 c5f5d0cd40e3bc2d6d397af788a7c0241b1c6b68 1. Don't hardcode "partition-" string twice 2. Use simpler logic & use ->name to avoid of_property_read_string() 3. Use mtd_get_of_node() helper Cc: Christian Marangi <ansuelsmth@gmail.com> Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-1-zajec5@gmail.com 
1. Don't hardcode "partition-" string twice
2. Use simpler logic & use ->name to avoid of_property_read_string()
3. Use mtd_get_of_node() helper

Cc: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-1-zajec5@gmail.com
mtd: core: add missing of_node_get() in dynamic partitions code 2022-10-18T08:16:38+00:00 Rafał Miłecki rafal@milecki.pl 2022-10-18T05:18:22+00:00 12b58961de0bd88b3c7dfa5d21f6d67f4678b780 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@nxp.com> Fixes: ad9b10d1eaada169 ("mtd: core: introduce of support for dynamic partitions") Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Tested-by: Han Xu <han.xu@nxp.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20221018051822.28685-1-zajec5@gmail.com 
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@nxp.com>
Fixes: ad9b10d1eaada169 ("mtd: core: introduce of support for dynamic partitions")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Tested-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221018051822.28685-1-zajec5@gmail.com