From: Chengming Zhou <zhouchengming@bytedance.com> mainline inclusion from mainline-v6.8-rc1 commit 8ba2f844f050a82624ba3ad5146aa3c116f506f7 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBLDIU CVE: CVE-2025-21693 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- First of all, we need to rename acomp_ctx->dstmem field to buffer, since we are now using for purposes other than compression. Then we change per-cpu mutex and buffer to per-acomp_ctx, since them belong to the acomp_ctx and are necessary parts when used in the compress/decompress contexts. So we can remove the old per-cpu mutex and dstmem. Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-5-9382162bbf05@bytedance.... Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Acked-by: Chris Li <chrisl@kernel.org> (Google) Reviewed-by: Nhat Pham <nphamcs@gmail.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Conflicts: include/linux/cpuhotplug.h mm/zswap.c [Ma Wupeng: Mainly context conflicts, no remove in enum cpuhp_state to make kabi stable] Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> --- include/linux/cpuhotplug.h | 2 +- mm/zswap.c | 104 ++++++++++++------------------------- 2 files changed, 34 insertions(+), 72 deletions(-) diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index b540e5a60ea9..ac109c61e882 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -86,7 +86,7 @@ enum cpuhp_state { CPUHP_ARM_BL_PREPARE, CPUHP_TRACE_RB_PREPARE, CPUHP_MM_ZS_PREPARE, - CPUHP_MM_ZSWP_MEM_PREPARE, + CPUHP_MM_ZSWP_MEM_PREPARE, /* keep this to make kabi stable */ CPUHP_MM_ZSWP_POOL_PREPARE, CPUHP_KVM_PPC_BOOK3S_PREPARE, CPUHP_ZCOMP_PREPARE, diff --git a/mm/zswap.c b/mm/zswap.c index d8e8d0084a22..5e495406555b 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -135,8 +135,8 @@ struct crypto_acomp_ctx { struct crypto_acomp *acomp; struct acomp_req *req; struct crypto_wait wait; - u8 *dstmem; - struct mutex *mutex; + u8 *buffer; + struct mutex mutex; }; struct zswap_pool { @@ -402,63 +402,26 @@ static struct zswap_entry *zswap_entry_find_get(struct rb_root *root, /********************************* * per-cpu code **********************************/ -static DEFINE_PER_CPU(u8 *, zswap_dstmem); -/* - * If users dynamically change the zpool type and compressor at runtime, i.e. - * zswap is running, zswap can have more than one zpool on one cpu, but they - * are sharing dtsmem. So we need this mutex to be per-cpu. - */ -static DEFINE_PER_CPU(struct mutex *, zswap_mutex); - -static int zswap_dstmem_prepare(unsigned int cpu) -{ - struct mutex *mutex; - u8 *dst; - - dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu)); - if (!dst) - return -ENOMEM; - - mutex = kmalloc_node(sizeof(*mutex), GFP_KERNEL, cpu_to_node(cpu)); - if (!mutex) { - kfree(dst); - return -ENOMEM; - } - - mutex_init(mutex); - per_cpu(zswap_dstmem, cpu) = dst; - per_cpu(zswap_mutex, cpu) = mutex; - return 0; -} - -static int zswap_dstmem_dead(unsigned int cpu) -{ - struct mutex *mutex; - u8 *dst; - - mutex = per_cpu(zswap_mutex, cpu); - kfree(mutex); - per_cpu(zswap_mutex, cpu) = NULL; - - dst = per_cpu(zswap_dstmem, cpu); - kfree(dst); - per_cpu(zswap_dstmem, cpu) = NULL; - - return 0; -} - static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node) { struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node); struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu); struct crypto_acomp *acomp; struct acomp_req *req; + int ret; + + mutex_init(&acomp_ctx->mutex); + + acomp_ctx->buffer = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu)); + if (!acomp_ctx->buffer) + return -ENOMEM; acomp = crypto_alloc_acomp_node(pool->tfm_name, 0, 0, cpu_to_node(cpu)); if (IS_ERR(acomp)) { pr_err("could not alloc crypto acomp %s : %ld\n", pool->tfm_name, PTR_ERR(acomp)); - return PTR_ERR(acomp); + ret = PTR_ERR(acomp); + goto acomp_fail; } acomp_ctx->acomp = acomp; @@ -466,8 +429,8 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node) if (!req) { pr_err("could not alloc crypto acomp_request %s\n", pool->tfm_name); - crypto_free_acomp(acomp_ctx->acomp); - return -ENOMEM; + ret = -ENOMEM; + goto req_fail; } acomp_ctx->req = req; @@ -480,10 +443,13 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node) acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, crypto_req_done, &acomp_ctx->wait); - acomp_ctx->mutex = per_cpu(zswap_mutex, cpu); - acomp_ctx->dstmem = per_cpu(zswap_dstmem, cpu); - return 0; + +req_fail: + crypto_free_acomp(acomp_ctx->acomp); +acomp_fail: + kfree(acomp_ctx->buffer); + return ret; } static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) @@ -496,6 +462,7 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) acomp_request_free(acomp_ctx->req); if (!IS_ERR_OR_NULL(acomp_ctx->acomp)) crypto_free_acomp(acomp_ctx->acomp); + kfree(acomp_ctx->buffer); } return 0; @@ -1009,14 +976,14 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle) acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); dlen = PAGE_SIZE; - mutex_lock(acomp_ctx->mutex); + mutex_lock(&acomp_ctx->mutex); sg_init_one(&input, src, entry->length); sg_init_table(&output, 1); sg_set_page(&output, page, PAGE_SIZE, 0); acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen); ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait); dlen = acomp_ctx->req->dlen; - mutex_unlock(acomp_ctx->mutex); + mutex_unlock(&acomp_ctx->mutex); BUG_ON(ret); BUG_ON(dlen != PAGE_SIZE); @@ -1175,13 +1142,17 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, /* compress */ acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); - mutex_lock(acomp_ctx->mutex); + mutex_lock(&acomp_ctx->mutex); - dst = acomp_ctx->dstmem; + dst = acomp_ctx->buffer; sg_init_table(&input, 1); sg_set_page(&input, page, PAGE_SIZE, 0); - /* zswap_dstmem is of size (PAGE_SIZE * 2). Reflect same in sg_list */ + /* + * We need PAGE_SIZE * 2 here since there maybe over-compression case, + * and hardware-accelerators may won't check the dst buffer size, so + * giving the dst buffer with enough length to avoid buffer overflow. + */ sg_init_one(&output, dst, PAGE_SIZE * 2); acomp_request_set_params(acomp_ctx->req, &input, &output, PAGE_SIZE, dlen); /* @@ -1222,7 +1193,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, memcpy(buf, &zhdr, hlen); memcpy(buf + hlen, dst, dlen); zpool_unmap_handle(entry->pool->zpool, handle); - mutex_unlock(acomp_ctx->mutex); + mutex_unlock(&acomp_ctx->mutex); /* populate entry */ entry->offset = offset; @@ -1250,7 +1221,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, return 0; put_dstmem: - mutex_unlock(acomp_ctx->mutex); + mutex_unlock(&acomp_ctx->mutex); zswap_pool_put(entry->pool); freepage: zswap_entry_cache_free(entry); @@ -1312,13 +1283,13 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset, } acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); - mutex_lock(acomp_ctx->mutex); + mutex_lock(&acomp_ctx->mutex); sg_init_one(&input, src, entry->length); sg_init_table(&output, 1); sg_set_page(&output, page, PAGE_SIZE, 0); acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen); ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait); - mutex_unlock(acomp_ctx->mutex); + mutex_unlock(&acomp_ctx->mutex); if (zpool_can_sleep_mapped(entry->pool->zpool)) zpool_unmap_handle(entry->pool->zpool, entry->handle); @@ -1466,13 +1437,6 @@ static int zswap_setup(void) goto cache_fail; } - ret = cpuhp_setup_state(CPUHP_MM_ZSWP_MEM_PREPARE, "mm/zswap:prepare", - zswap_dstmem_prepare, zswap_dstmem_dead); - if (ret) { - pr_err("dstmem alloc failed\n"); - goto dstmem_fail; - } - ret = cpuhp_setup_state_multi(CPUHP_MM_ZSWP_POOL_PREPARE, "mm/zswap_pool:prepare", zswap_cpu_comp_prepare, @@ -1505,8 +1469,6 @@ static int zswap_setup(void) if (pool) zswap_pool_destroy(pool); hp_fail: - cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE); -dstmem_fail: zswap_entry_cache_destroy(); cache_fail: /* if built-in, we aren't unloaded on failure; don't allow use */ -- 2.43.0