[PATCH v4 2/2] ubifs: use strscpy() and kmemdup_nul() where appropriate

[Dmitry Antipov]

On Fri, 2026-04-10 at 07:57 +0200, Richard Weinberger wrote:

> Dmitry, how are you testing these changes?

Build with:

CONFIG_KASAN=y

CONFIG_MTD_NAND_NANDSIM=m

CONFIG_MTD_UBI=m
CONFIG_MTD_UBI_WL_THRESHOLD=4096
CONFIG_MTD_UBI_BEB_LIMIT=20
CONFIG_UBIFS_FS=m
CONFIG_UBIFS_FS_ADVANCED_COMPR=y
CONFIG_UBIFS_FS_LZO=y
CONFIG_UBIFS_FS_ZLIB=y
CONFIG_UBIFS_FS_ZSTD=y
CONFIG_UBIFS_ATIME_SUPPORT=y
CONFIG_UBIFS_FS_XATTR=y
CONFIG_UBIFS_FS_SECURITY=y
CONFIG_UBIFS_FS_AUTHENTICATION=y

and boot (QEMU VM), then:

# modprobe nandsim second_id_byte=0xdc third_id_byte=0x80 fourth_id_byte=0x1d
[   24.282259] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0
[   24.282787] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0
[   24.283441] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0
[   24.284083] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0
[   24.284783] [nandsim] warning: read_byte: unexpected data output cycle, state is STATE_READY return 0x0
[   24.285473] nand: device found, Manufacturer ID: 0x98, Chip ID: 0xdc
[   24.285932] nand: Toshiba NAND 512MiB 3,3V 8-bit
[   24.286275] nand: 512 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
[   24.286749] flash size: 512 MiB
[   24.286925] page size: 2048 bytes
[   24.287104] OOB area size: 64 bytes
[   24.287337] sector size: 128 KiB
[   24.287578] pages number: 262144
[   24.287817] pages per sector: 64
[   24.288068] bus width: 8
[   24.288269] bits in sector size: 17
[   24.288527] bits in page size: 11
[   24.288775] bits in OOB size: 6
[   24.289024] flash size with OOB: 540672 KiB
[   24.289334] page address bytes: 5
[   24.289572] sector address bytes: 3
[   24.289837] options: 0x8
[   24.290676] Scanning device for bad blocks
[   24.311973] Creating 1 MTD partitions on "NAND 512MiB 3,3V 8-bit":
[   24.312376] 0x000000000000-0x000020000000 : "NAND simulator partition 0"

# modprobe ubi mtd=0
[   44.884572] ubi0: attaching mtd0
[   44.893002] ubi0: scanning is finished
[   44.893308] ubi0: empty MTD device detected
[   44.947667] ubi0: attached mtd0 (name "NAND 512MiB 3,3V 8-bit", size 512 MiB)
[   44.948231] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 129024 bytes
[   44.948719] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 512
[   44.949206] ubi0: VID header offset: 512 (aligned 512), data offset: 2048
[   44.949686] ubi0: good PEBs: 4096, bad PEBs: 0, corrupted PEBs: 0
[   44.950113] ubi0: user volume: 0, internal volumes: 1, max. volumes count: 128
[   44.950639] ubi0: max/mean erase counter: 0/0, WL threshold: 4096, image sequence number: 3902257690
[   44.951285] ubi0: available PEBs: 4012, total reserved PEBs: 84, PEBs reserved for bad PEB handling: 80
[   44.951946] ubi0: background thread "ubi_bgt0d" started, PID 1022

# ubimkvol /dev/ubi0 -N test -m
Set volume size to 517644288
Volume ID 0, size 4012 LEBs (517644288 bytes, 493.6 MiB), LEB size 129024 bytes (126.0 KiB), dynamic, name "test", alignment 1

# mount -t ubifs ubi0:test /mnt/ubifs
[  122.812026] UBIFS (ubi0:0): default file-system created
[  122.812377] UBIFS (ubi0:0): Mounting in unauthenticated mode
[  122.813415] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" started, PID 1053
[  122.813963] UBIFS (ubi0:0): UBIFS: mounted UBI device 0, volume 0, name "test"
[  122.814334] UBIFS (ubi0:0): LEB size: 129024 bytes (126 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[  122.814849] UBIFS (ubi0:0): FS size: 515579904 bytes (491 MiB, 3996 LEBs), max 4012 LEBs, journal size 25804800 bytes (24 MiB, 200 LEBs)
[  122.815701] UBIFS (ubi0:0): reserved for root: 4952683 bytes (4836 KiB)
[  122.816225] UBIFS (ubi0:0): media format: w5/r0 (latest is w5/r0), UUID 999464F1-4417-4523-B773-57C6EBD728DC, small LPT model
[  122.817041] UBIFS (ubi0:0): full atime support is enabled.

# cp -a [~390M source tree] /mnt/ubifs
# diff -ur [tree] /mnt/ubifs/[copy of that tree] ; no output hopefully means OK

# umount /mnt/ubifs
[  179.322533] UBIFS (ubi0:0): un-mount UBI device 0
[  179.323801] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" stops

# mount -t ubifs ubi0:test /mnt/ubifs
[  185.313439] UBIFS (ubi0:0): Mounting in unauthenticated mode
...

# diff -ur [tree] /mnt/ubifs/[copy of that tree] ; likewise

etc.

Dmitry