From e5126de138caef0eedb3d6431059c0c5581a1a5d Mon Sep 17 00:00:00 2001 From: Yue Hu Date: Fri, 21 Oct 2022 16:53:25 +0800 Subject: [PATCH 1/5] erofs: fix general protection fault when reading fragment As syzbot reported [1], the fragment feature sb flag is not set, so packed_inode != NULL needs to be checked in z_erofs_read_fragment(). [1] https://lore.kernel.org/all/0000000000002e7a8905eb841ddd@google.com/ Reported-by: syzbot+3faecbfd845a895c04cb@syzkaller.appspotmail.com Fixes: b15b2e307c3a ("erofs: support on-disk compressed fragments data") Signed-off-by: Yue Hu Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20221021085325.25788-1-zbestahu@gmail.com Signed-off-by: Gao Xiang --- fs/erofs/zdata.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index c7f24fc7efd5..d6caf275be77 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -660,6 +660,9 @@ static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos, u8 *src, *dst; unsigned int i, cnt; + if (!packed_inode) + return -EFSCORRUPTED; + pos += EROFS_I(inode)->z_fragmentoff; for (i = 0; i < len; i += cnt) { cnt = min_t(unsigned int, len - i, From 75e43355cbe4d5948a79bd592f2ffecb9f75f75d Mon Sep 17 00:00:00 2001 From: Jingbo Xu Date: Fri, 4 Nov 2022 13:40:27 +0800 Subject: [PATCH 2/5] erofs: put metabuf in error path in fscache mode For tail packing layout, put metabuf when error is encountered. Fixes: 1ae9470c3e14 ("erofs: clean up .read_folio() and .readahead() in fscache mode") Signed-off-by: Jingbo Xu Reviewed-by: Gao Xiang Reviewed-by: Jia Zhu Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20221104054028.52208-2-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang --- fs/erofs/fscache.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index fe05bc51f9f2..83559008bfa8 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -287,8 +287,10 @@ static int erofs_fscache_data_read(struct address_space *mapping, return PTR_ERR(src); iov_iter_xarray(&iter, READ, &mapping->i_pages, pos, PAGE_SIZE); - if (copy_to_iter(src + offset, size, &iter) != size) + if (copy_to_iter(src + offset, size, &iter) != size) { + erofs_put_metabuf(&buf); return -EFAULT; + } iov_iter_zero(PAGE_SIZE - size, &iter); erofs_put_metabuf(&buf); return PAGE_SIZE; From e6d9f9ba111b56154f1b1120252aff269cebd49c Mon Sep 17 00:00:00 2001 From: Jingbo Xu Date: Fri, 4 Nov 2022 13:40:28 +0800 Subject: [PATCH 3/5] erofs: get correct count for unmapped range in fscache mode For unmapped range, the returned map.m_llen is zero, and thus the calculated count is unexpected zero. Prior to the refactoring introduced by commit 1ae9470c3e14 ("erofs: clean up .read_folio() and .readahead() in fscache mode"), only the readahead routine suffers from this. With the refactoring of making .read_folio() and .readahead() calling one common routine, both read_folio and readahead have this issue now. Fix this by calculating count separately in unmapped condition. Fixes: c665b394b9e8 ("erofs: implement fscache-based data readahead") Fixes: 1ae9470c3e14 ("erofs: clean up .read_folio() and .readahead() in fscache mode") Signed-off-by: Jingbo Xu Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20221104054028.52208-3-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang --- fs/erofs/fscache.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index 83559008bfa8..260fa4737fc0 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -296,15 +296,16 @@ static int erofs_fscache_data_read(struct address_space *mapping, return PAGE_SIZE; } - count = min_t(size_t, map.m_llen - (pos - map.m_la), len); - DBG_BUGON(!count || count % PAGE_SIZE); - if (!(map.m_flags & EROFS_MAP_MAPPED)) { + count = len; iov_iter_xarray(&iter, READ, &mapping->i_pages, pos, count); iov_iter_zero(count, &iter); return count; } + count = min_t(size_t, map.m_llen - (pos - map.m_la), len); + DBG_BUGON(!count || count % PAGE_SIZE); + mdev = (struct erofs_map_dev) { .m_deviceid = map.m_deviceid, .m_pa = map.m_pa, From 39bfcb8138f6dc3375f23b1e62ccfc7c0d83295d Mon Sep 17 00:00:00 2001 From: Jingbo Xu Date: Fri, 21 Oct 2022 10:31:53 +0800 Subject: [PATCH 4/5] erofs: fix use-after-free of fsid and domain_id string When erofs instance is remounted with fsid or domain_id mount option specified, the original fsid and domain_id string pointer in sbi->opt is directly overridden with the fsid and domain_id string in the new fs_context, without freeing the original fsid and domain_id string. What's worse, when the new fsid and domain_id string is transferred to sbi, they are not reset to NULL in fs_context, and thus they are freed when remount finishes, while sbi is still referring to these strings. Reconfiguration for fsid and domain_id seems unusual. Thus clarify this restriction explicitly and dump a warning when users are attempting to do this. Besides, to fix the use-after-free issue, move fsid and domain_id from erofs_mount_opts to outside. Fixes: c6be2bd0a5dd ("erofs: register fscache volume") Fixes: 8b7adf1dff3d ("erofs: introduce fscache-based domain") Signed-off-by: Jingbo Xu Reviewed-by: Jia Zhu Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20221021023153.1330-1-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang --- fs/erofs/fscache.c | 14 +++++++------- fs/erofs/internal.h | 6 ++++-- fs/erofs/super.c | 39 ++++++++++++++++++++++----------------- fs/erofs/sysfs.c | 8 ++++---- 4 files changed, 37 insertions(+), 30 deletions(-) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index 260fa4737fc0..6eaf4a4ab95c 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -406,13 +406,13 @@ static void erofs_fscache_domain_put(struct erofs_domain *domain) static int erofs_fscache_register_volume(struct super_block *sb) { struct erofs_sb_info *sbi = EROFS_SB(sb); - char *domain_id = sbi->opt.domain_id; + char *domain_id = sbi->domain_id; struct fscache_volume *volume; char *name; int ret = 0; name = kasprintf(GFP_KERNEL, "erofs,%s", - domain_id ? domain_id : sbi->opt.fsid); + domain_id ? domain_id : sbi->fsid); if (!name) return -ENOMEM; @@ -438,7 +438,7 @@ static int erofs_fscache_init_domain(struct super_block *sb) if (!domain) return -ENOMEM; - domain->domain_id = kstrdup(sbi->opt.domain_id, GFP_KERNEL); + domain->domain_id = kstrdup(sbi->domain_id, GFP_KERNEL); if (!domain->domain_id) { kfree(domain); return -ENOMEM; @@ -475,7 +475,7 @@ static int erofs_fscache_register_domain(struct super_block *sb) mutex_lock(&erofs_domain_list_lock); list_for_each_entry(domain, &erofs_domain_list, list) { - if (!strcmp(domain->domain_id, sbi->opt.domain_id)) { + if (!strcmp(domain->domain_id, sbi->domain_id)) { sbi->domain = domain; sbi->volume = domain->volume; refcount_inc(&domain->ref); @@ -612,7 +612,7 @@ struct erofs_fscache *erofs_domain_register_cookie(struct super_block *sb, struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb, char *name, bool need_inode) { - if (EROFS_SB(sb)->opt.domain_id) + if (EROFS_SB(sb)->domain_id) return erofs_domain_register_cookie(sb, name, need_inode); return erofs_fscache_acquire_cookie(sb, name, need_inode); } @@ -644,7 +644,7 @@ int erofs_fscache_register_fs(struct super_block *sb) struct erofs_sb_info *sbi = EROFS_SB(sb); struct erofs_fscache *fscache; - if (sbi->opt.domain_id) + if (sbi->domain_id) ret = erofs_fscache_register_domain(sb); else ret = erofs_fscache_register_volume(sb); @@ -652,7 +652,7 @@ int erofs_fscache_register_fs(struct super_block *sb) return ret; /* acquired domain/volume will be relinquished in kill_sb() on error */ - fscache = erofs_fscache_register_cookie(sb, sbi->opt.fsid, true); + fscache = erofs_fscache_register_cookie(sb, sbi->fsid, true); if (IS_ERR(fscache)) return PTR_ERR(fscache); diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 1701df48c446..05dc68627722 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -75,8 +75,6 @@ struct erofs_mount_opts { unsigned int max_sync_decompress_pages; #endif unsigned int mount_opt; - char *fsid; - char *domain_id; }; struct erofs_dev_context { @@ -89,6 +87,8 @@ struct erofs_dev_context { struct erofs_fs_context { struct erofs_mount_opts opt; struct erofs_dev_context *devs; + char *fsid; + char *domain_id; }; /* all filesystem-wide lz4 configurations */ @@ -170,6 +170,8 @@ struct erofs_sb_info { struct fscache_volume *volume; struct erofs_fscache *s_fscache; struct erofs_domain *domain; + char *fsid; + char *domain_id; }; #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info) diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 2cf96ce1c32e..1c7dcca702b3 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -579,9 +579,9 @@ static int erofs_fc_parse_param(struct fs_context *fc, break; case Opt_fsid: #ifdef CONFIG_EROFS_FS_ONDEMAND - kfree(ctx->opt.fsid); - ctx->opt.fsid = kstrdup(param->string, GFP_KERNEL); - if (!ctx->opt.fsid) + kfree(ctx->fsid); + ctx->fsid = kstrdup(param->string, GFP_KERNEL); + if (!ctx->fsid) return -ENOMEM; #else errorfc(fc, "fsid option not supported"); @@ -589,9 +589,9 @@ static int erofs_fc_parse_param(struct fs_context *fc, break; case Opt_domain_id: #ifdef CONFIG_EROFS_FS_ONDEMAND - kfree(ctx->opt.domain_id); - ctx->opt.domain_id = kstrdup(param->string, GFP_KERNEL); - if (!ctx->opt.domain_id) + kfree(ctx->domain_id); + ctx->domain_id = kstrdup(param->string, GFP_KERNEL); + if (!ctx->domain_id) return -ENOMEM; #else errorfc(fc, "domain_id option not supported"); @@ -728,10 +728,12 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_fs_info = sbi; sbi->opt = ctx->opt; - ctx->opt.fsid = NULL; - ctx->opt.domain_id = NULL; sbi->devs = ctx->devs; ctx->devs = NULL; + sbi->fsid = ctx->fsid; + ctx->fsid = NULL; + sbi->domain_id = ctx->domain_id; + ctx->domain_id = NULL; if (erofs_is_fscache_mode(sb)) { sb->s_blocksize = EROFS_BLKSIZ; @@ -820,7 +822,7 @@ static int erofs_fc_get_tree(struct fs_context *fc) { struct erofs_fs_context *ctx = fc->fs_private; - if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && ctx->opt.fsid) + if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && ctx->fsid) return get_tree_nodev(fc, erofs_fc_fill_super); return get_tree_bdev(fc, erofs_fc_fill_super); @@ -834,6 +836,9 @@ static int erofs_fc_reconfigure(struct fs_context *fc) DBG_BUGON(!sb_rdonly(sb)); + if (ctx->fsid || ctx->domain_id) + erofs_info(sb, "ignoring reconfiguration for fsid|domain_id."); + if (test_opt(&ctx->opt, POSIX_ACL)) fc->sb_flags |= SB_POSIXACL; else @@ -873,8 +878,8 @@ static void erofs_fc_free(struct fs_context *fc) struct erofs_fs_context *ctx = fc->fs_private; erofs_free_dev_context(ctx->devs); - kfree(ctx->opt.fsid); - kfree(ctx->opt.domain_id); + kfree(ctx->fsid); + kfree(ctx->domain_id); kfree(ctx); } @@ -944,8 +949,8 @@ static void erofs_kill_sb(struct super_block *sb) erofs_free_dev_context(sbi->devs); fs_put_dax(sbi->dax_dev, NULL); erofs_fscache_unregister_fs(sb); - kfree(sbi->opt.fsid); - kfree(sbi->opt.domain_id); + kfree(sbi->fsid); + kfree(sbi->domain_id); kfree(sbi); sb->s_fs_info = NULL; } @@ -1098,10 +1103,10 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root) if (test_opt(opt, DAX_NEVER)) seq_puts(seq, ",dax=never"); #ifdef CONFIG_EROFS_FS_ONDEMAND - if (opt->fsid) - seq_printf(seq, ",fsid=%s", opt->fsid); - if (opt->domain_id) - seq_printf(seq, ",domain_id=%s", opt->domain_id); + if (sbi->fsid) + seq_printf(seq, ",fsid=%s", sbi->fsid); + if (sbi->domain_id) + seq_printf(seq, ",domain_id=%s", sbi->domain_id); #endif return 0; } diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c index 783bb7b21b51..fd476961f742 100644 --- a/fs/erofs/sysfs.c +++ b/fs/erofs/sysfs.c @@ -210,14 +210,14 @@ int erofs_register_sysfs(struct super_block *sb) int err; if (erofs_is_fscache_mode(sb)) { - if (sbi->opt.domain_id) { - str = kasprintf(GFP_KERNEL, "%s,%s", sbi->opt.domain_id, - sbi->opt.fsid); + if (sbi->domain_id) { + str = kasprintf(GFP_KERNEL, "%s,%s", sbi->domain_id, + sbi->fsid); if (!str) return -ENOMEM; name = str; } else { - name = sbi->opt.fsid; + name = sbi->fsid; } } else { name = sb->s_id; From 37020bbb71d911431e16c2c940b97cf86ae4f2f6 Mon Sep 17 00:00:00 2001 From: Jingbo Xu Date: Mon, 14 Nov 2022 20:19:43 +0800 Subject: [PATCH 5/5] erofs: fix missing xas_retry() in fscache mode The xarray iteration only holds the RCU read lock and thus may encounter XA_RETRY_ENTRY if there's process modifying the xarray concurrently. This will cause oops when referring to the invalid entry. Fix this by adding the missing xas_retry(), which will make the iteration wind back to the root node if XA_RETRY_ENTRY is encountered. Fixes: d435d53228dd ("erofs: change to use asynchronous io for fscache readpage/readahead") Suggested-by: David Howells Reviewed-by: Gao Xiang Reviewed-by: Jia Zhu Signed-off-by: Jingbo Xu Link: https://lore.kernel.org/r/20221114121943.29987-1-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang --- fs/erofs/fscache.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index 6eaf4a4ab95c..af5ed6b9c54d 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -75,11 +75,15 @@ static void erofs_fscache_rreq_unlock_folios(struct netfs_io_request *rreq) rcu_read_lock(); xas_for_each(&xas, folio, last_page) { - unsigned int pgpos = - (folio_index(folio) - start_page) * PAGE_SIZE; - unsigned int pgend = pgpos + folio_size(folio); + unsigned int pgpos, pgend; bool pg_failed = false; + if (xas_retry(&xas, folio)) + continue; + + pgpos = (folio_index(folio) - start_page) * PAGE_SIZE; + pgend = pgpos + folio_size(folio); + for (;;) { if (!subreq) { pg_failed = true;