From: Liyuan Pang Date: Fri, 7 Nov 2025 10:00:57 +0000 (+0800) Subject: ubi: fastmap: fix ubi->fm memory leak X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d133e30aabc7c8eb8206827f8fbe0f3679adb911;p=thirdparty%2Fkernel%2Flinux.git ubi: fastmap: fix ubi->fm memory leak 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 --- diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c index adc47b87b38a5..884171871d0e5 100644 --- a/drivers/mtd/ubi/attach.c +++ b/drivers/mtd/ubi/attach.c @@ -1600,7 +1600,7 @@ int ubi_attach(struct ubi_device *ubi, int force_scan) err = ubi_read_volume_table(ubi, ai); if (err) - goto out_ai; + goto out_fm; err = ubi_wl_init(ubi, ai); if (err) @@ -1642,6 +1642,8 @@ out_wl: out_vtbl: ubi_free_all_volumes(ubi); vfree(ubi->vtbl); +out_fm: + ubi_free_fastmap(ubi); out_ai: destroy_ai(ai); return err; diff --git a/drivers/mtd/ubi/fastmap-wl.c b/drivers/mtd/ubi/fastmap-wl.c index 9bdb6525f1281..e2bc1122bfd31 100644 --- a/drivers/mtd/ubi/fastmap-wl.c +++ b/drivers/mtd/ubi/fastmap-wl.c @@ -530,8 +530,6 @@ int ubi_is_erase_work(struct ubi_work *wrk) static void ubi_fastmap_close(struct ubi_device *ubi) { - int i; - return_unused_pool_pebs(ubi, &ubi->fm_pool); return_unused_pool_pebs(ubi, &ubi->fm_wl_pool); @@ -540,11 +538,7 @@ static void ubi_fastmap_close(struct ubi_device *ubi) ubi->fm_anchor = NULL; } - if (ubi->fm) { - for (i = 0; i < ubi->fm->used_blocks; i++) - kfree(ubi->fm->e[i]); - } - kfree(ubi->fm); + ubi_free_fastmap(ubi); } /** diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index c792b9bcab9bc..44803d3329f42 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -969,10 +969,22 @@ int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai, struct ubi_attach_info *scan_ai); int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count); void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol); +static inline void ubi_free_fastmap(struct ubi_device *ubi) +{ + if (ubi->fm) { + int i; + + for (i = 0; i < ubi->fm->used_blocks; i++) + kmem_cache_free(ubi_wl_entry_slab, ubi->fm->e[i]); + kfree(ubi->fm); + ubi->fm = NULL; + } +} #else static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; } static inline int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count) { return 0; } static inline void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol) {} +static inline void ubi_free_fastmap(struct ubi_device *ubi) { } #endif /* block.c */