kernel/linux.git/drivers/mtd, branch v6.12.107

ubi: fastmap: fix ubi->fm memory leak

2026-08-23T12:22:35+00:00

[ Upstream commit d133e30aabc7c8eb8206827f8fbe0f3679adb911 ] The problem is that scan_fast() allocate memory for ubi->fm and ubi->fm->e[x], but if the following attach process fails in ubi_wl_init or ubi_read_volume_table, the whole attach process will fail without executing ubi_wl_close to free the memory under ubi->fm. Fix this by add a new ubi_free_fastmap function in fastmap.c to free the memory allocated for fm. If SLUB_DEBUG and KUNIT are enabled, the following warning messages will show: ubi0: detaching mtd0 ubi0: mtd0 is detached ubi0: default fastmap pool size: 200 ubi0: default fastmap WL pool size: 100 ubi0: attaching mtd0 ubi0: attached by fastmap ubi0: fastmap pool size: 200 ubi0: fastmap WL pool size: 100 ubi0 error: ubi_wl_init [ubi]: no enough physical eraseblocks (4, need 203) ubi0 error: ubi_attach_mtd_dev [ubi]: failed to attach mtd0, error -28 UBI error: cannot attach mtd0 ================================================================= BUG ubi_wl_entry_slab (Tainted: G B O L ): Objects remaining in ubi_wl_entry_slab on __kmem_cache_shutdown() ----------------------------------------------------------------------------- Slab 0xffff2fd23a40cd00 objects=22 used=1 fp=0xffff2fd1d0334fd8 flags=0x883fffc010200(slab|head|section=34|node=0|zone=1|lastcpupid=0x7fff) CPU: 0 PID: 5884 Comm: insmod Tainted: G B O L 5.10.0 #1 Hardware name: LS1043A RDB Board (DT) Call trace: dump_backtrace+0x0/0x198 show_stack+0x18/0x28 dump_stack+0xe8/0x15c slab_err+0x94/0xc0 __kmem_cache_shutdown+0x1fc/0x39c kmem_cache_destroy+0x48/0x138 ubi_init+0x1d4/0xf34 [ubi] do_one_initcall+0xb4/0x24c do_init_module+0x4c/0x1dc load_module+0x212c/0x2260 __se_sys_finit_module+0xb4/0xd8 __arm64_sys_finit_module+0x18/0x28 el0_svc_common.constprop.0+0x78/0x1a0 do_el0_svc+0x78/0x90 el0_svc+0x20/0x38 el0_sync_handler+0xf0/0x140 normal+0x3d8/0x400 Object 0xffff2fd1d0334e68 @offset=3688 Allocated in ubi_scan_fastmap+0xf04/0xf40 [ubi] age=80 cpu=0 pid=5884 __slab_alloc.isra.21+0x6c/0xb4 kmem_cache_alloc+0x1e4/0x80c ubi_scan_fastmap+0xf04/0xf40 [ubi] ubi_attach+0x1f0/0x3a8 [ubi] ubi_attach_mtd_dev+0x810/0xbc8 [ubi] ubi_init+0x238/0xf34 [ubi] do_one_initcall+0xb4/0x24c do_init_module+0x4c/0x1dc load_module+0x212c/0x2260 __se_sys_finit_module+0xb4/0xd8 __arm64_sys_finit_module+0x18/0x28 el0_svc_common.constprop.0+0x78/0x1a0 do_el0_svc+0x78/0x90 el0_svc+0x20/0x38 el0_sync_handler+0xf0/0x140 normal+0x3d8/0x400 Link: https://bugzilla.kernel.org/show_bug.cgi?id=220744 Signed-off-by: Liyuan Pang Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

mtd: ubi: skip programming unused bits in ubi headers

2026-08-23T12:22:35+00:00

[ Upstream commit 77530d1a78ca5c274e37d6494a965223672630b2 ] This patch prevents unnecessary programming of bits in ec_hdr and vid_hdr that are not used or read during normal UBI operation. These unused bits are typcially already set to 1 in erased flash and do not need to be explicitly programmed to 0 if they are not used. Programming such unused areas offers no functional benefit and may result in unnecessary flash wear, reducing the overall lifetime of the device. By skipping these writes, we preserve the flash state as much as possible and minimize wear caused by redundant operations. This change ensures that only necessary fields are written when preparing UBI headers, improving flash efficiency without affecting functionality. Additionally, the Kioxia TC58NVG1S3HTA00 datasheet (page 63) also notes that continuous program/erase cycling with a high percentage of '0' bits in the data pattern can accelerate block endurance degradation. This further supports avoiding large 0x00 patterns. Link: https://europe.kioxia.com/content/dam/kioxia/newidr/productinfo/datasheet/201910/DST_TC58NVG1S3HTA00-TDE_EN_31442.pdf Signed-off-by: Cheng Ming Lin Reviewed-by: Miquel Raynal Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

mtd: spinand: repeat reading in regular mode if continuous reading fails

2026-08-19T16:14:15+00:00

[ Upstream commit 010dc7f2dd6a0078ade3f88f627ed5fbf45ceb94 ] Continuous reading may result in multiple flash pages reading in one operation. Unfortunately, not all spinand controllers support such large reading. They will read less data. Unfortunately, the operation can't be continued. In this case: * disable continuous reading on this (not good enough) spi controller * repeat reading in regular mode. Cc: stable@vger.kernel.org Signed-off-by: Mikhail Kshevetskiy Signed-off-by: Miquel Raynal Signed-off-by: Frieder Schrempf Signed-off-by: Sasha Levin

mtd: spinand: try a regular dirmap if creating a dirmap for continuous reading fails

2026-08-19T16:14:15+00:00

[ Upstream commit 004f8ea0d9917398aabff7388b3bf62a84a4088b ] Continuous reading may result in multiple flash pages reading in one operation. Typically only one flash page has read/written (a little bit more than 2-4 Kb), but continuous reading requires the spi controller to read up to 512 Kb in one operation without toggling CS in beetween. Roughly speaking spi controllers can be divided on 2 categories: * spi controllers without dirmap acceleration support * spi controllers with dirmap acceleration support Firt of them will have issues with continuous reading if restriction on the transfer length is implemented in the adjust_op_size() handler. Second group often supports acceleration of single page only reading. Thus enabling of continuous reading can break flash reading. This patch tries to create dirmap for continuous reading first and fallback to regular reading if spi controller refuses to create it. Cc: stable@vger.kernel.org Signed-off-by: Mikhail Kshevetskiy Signed-off-by: Miquel Raynal Signed-off-by: Frieder Schrempf Signed-off-by: Sasha Levin

mtd: spinand: fix direct mapping creation sizes

2026-08-19T16:14:15+00:00

[ Upstream commit e4a0cf9f1d90e6888e5373da3314f761024f6c97 ] Continuous mode is only supported for data reads, thus writing requires only single flash page mapping. Cc: stable@vger.kernel.org Signed-off-by: Mikhail Kshevetskiy Signed-off-by: Miquel Raynal Signed-off-by: Frieder Schrempf Signed-off-by: Sasha Levin

mtd: maps: vmu-flash: fix fault in unaligned fixup

2026-08-03T09:17:34+00:00

[ Upstream commit 79d1661502c6e4b6f626185cef72cf2fa78116e1 ] Use kzalloc_obj() / kzalloc_objs() to allocate the memcard structs, instead of kmalloc_obj() / kmalloc_objs() to prevent access to uninitialized data. Fixes runtime error: Fault in unaligned fixup: 0000 [#1] at mtd_get_fact_prot_info. Fixes: 47a72688fae7 ("mtd: flash mapping support for Dreamcast VMU.") Cc: stable@vger.kernel.org Signed-off-by: Florian Fuchs Signed-off-by: Miquel Raynal Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

mtd: fix double free and WARN_ON in add_mtd_device() error paths

2026-08-03T09:17:01+00:00

[ Upstream commit 9d4af746af8ce27eefc2338b2feaa1e01f28b6c3 ] When device_register() or mtd_nvmem_add() fails inside add_mtd_device() for a partition, the error handling triggers mtd_release() via put_device() or device_unregister(). mtd_release() calls release_mtd_partition() which frees the mtd_info structure. However, callers such as mtd_add_partition() and add_mtd_partitions() also call free_partition() in their error paths, resulting in a double free. Additionally, release_mtd_partition() hits WARN_ON(!list_empty( &mtd->part.node)) because the partition node is still linked in the parent's partitions list when the release callback fires from the add_mtd_device() error path. Fix this by overriding dev->type and dev->release before put_device() in the error paths, so that device_release() invokes a no-op function instead of mtd_release(). For the mtd_nvmem_add() failure case, device_unregister() is replaced with device_del() to separate the device removal from the final kobject reference drop, allowing the override to take effect before put_device() is called. The callers' error paths (list_del + free_partition) remain the sole owners of mtd_info lifetime on add_mtd_device() failure, which is the expected contract. The normal partition teardown path is not affected: del_mtd_device() goes through kref_put() -> mtd_device_release() -> device_unregister() with dev->type still set to &mtd_devtype, so mtd_release() -> release_mtd_partition() continues to work correctly for the regular removal case. Reported-by: syzbot+e9c76b56dc05023b8117@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=e9c76b56dc05023b8117 Fixes: 19bfa9ebebb5 ("mtd: use refcount to prevent corruption") Signed-off-by: Xue Lei Signed-off-by: Miquel Raynal Signed-off-by: Sasha Levin

mtd: nand: mtk-ecc: stop on ECC idle timeouts

2026-08-03T09:17:01+00:00

[ Upstream commit 16f7ec8d5dc100eafd2c8e06cd30340a30b104a1 ] mtk_ecc_wait_idle() logs when the encoder or decoder does not become idle, but returns void. Callers can therefore configure a non-idle ECC engine or read parity bytes after an unconfirmed encoder idle state. Return the idle poll result and propagate it from the enable and encode paths that require the engine to be idle before continuing. Fixes: 1d6b1e464950 ("mtd: mediatek: driver for MTK Smart Device") Signed-off-by: Pengpeng Hou Signed-off-by: Miquel Raynal Signed-off-by: Sasha Levin

mtd: mtdswap: remove debugfs stats file on teardown

2026-08-03T09:17:01+00:00

[ Upstream commit 66fb31358108d10245b9e4ef0eef3e7d9747055e ] mtdswap_add_debugfs() creates an mtdswap_stats debugfs file under the per-MTD debugfs directory, but mtdswap_remove_dev() never removes it before freeing the mtdswap_dev. Store the returned dentry and remove it during device teardown before the driver-private state is freed. Fixes: a32159024620 ("mtd: Add mtdswap block driver") Signed-off-by: Pengpeng Hou Signed-off-by: Miquel Raynal Signed-off-by: Sasha Levin

mtd: rawnand: lpc32xx_slc: fail DMA transfer on completion timeout

2026-07-24T14:11:47+00:00

commit 17a8ce84964f243c8f89dc7353ac7e8d3137bc74 upstream. lpc32xx_xmit_dma() waits for the DMA completion callback but ignores wait_for_completion_timeout(). A timed out DMA transfer is therefore unmapped and reported as successful to the NAND read/write path. Return -ETIMEDOUT when the completion wait expires. Terminate the DMA channel before unmapping the scatterlist so the timed out transfer cannot continue to access the buffer after the error is returned. Fixes: 2944a44da09e ("mtd: add LPC32xx SLC NAND driver") Cc: stable@vger.kernel.org Reviewed-by: Vladimir Zapolskiy Signed-off-by: Pengpeng Hou Signed-off-by: Miquel Raynal Signed-off-by: Greg Kroah-Hartman