Patch "mtd: core: fix possible resource leak in init_mtd()" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    mtd: core: fix possible resource leak in init_mtd()

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mtd-core-fix-possible-resource-leak-in-init_mtd.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit f5cc75377b56487cbf4b798b1ec41aeb6f0ddae6
Author: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>
Date:   Mon Oct 24 14:51:09 2022 +0800

    mtd: core: fix possible resource leak in init_mtd()
    
    [ Upstream commit 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@xxxxxxxxxx>
    Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
    Link: https://lore.kernel.org/linux-mtd/20221024065109.2050705-1-cuigaosheng1@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index a16627455c1d..675305139a54 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -2485,6 +2485,7 @@ 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);