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* [PATCH] mtd: core: fix possible resource leak in init_mtd()
@ 2022-10-24  6:51 Gaosheng Cui
  2022-11-07 16:20 ` Miquel Raynal
  0 siblings, 1 reply; 2+ messages in thread
From: Gaosheng Cui @ 2022-10-24  6:51 UTC (permalink / raw)
  To: miquel.raynal, richard, vigneshr, marek.vasut, jim_baxter,
	computersforpeace, Sandeep_Jain, cuigaosheng1
  Cc: linux-mtd

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>
---
 drivers/mtd/mtdcore.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 20fcedc3021e..d856892cb9b7 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -2475,6 +2475,7 @@ static int __init init_mtd(void)
 out_procfs:
 	if (proc_mtd)
 		remove_proc_entry("mtd", NULL);
+	bdi_unregister(mtd_bdi);
 	bdi_put(mtd_bdi);
 err_bdi:
 	class_unregister(&mtd_class);
-- 
2.25.1


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^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] mtd: core: fix possible resource leak in init_mtd()
  2022-10-24  6:51 [PATCH] mtd: core: fix possible resource leak in init_mtd() Gaosheng Cui
@ 2022-11-07 16:20 ` Miquel Raynal
  0 siblings, 0 replies; 2+ messages in thread
From: Miquel Raynal @ 2022-11-07 16:20 UTC (permalink / raw)
  To: Gaosheng Cui, miquel.raynal, richard, vigneshr, marek.vasut,
	jim_baxter, computersforpeace, Sandeep_Jain
  Cc: linux-mtd

On Mon, 2022-10-24 at 06:51:09 UTC, Gaosheng Cui wrote:
> 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>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/next, thanks.

Miquel

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http://lists.infradead.org/mailman/listinfo/linux-mtd/

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2022-11-07 16:31 UTC | newest]

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2022-10-24  6:51 [PATCH] mtd: core: fix possible resource leak in init_mtd() Gaosheng Cui
2022-11-07 16:20 ` Miquel Raynal

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