kernel/linux.git/fs/ubifs, branch v6.1.174

ubifs: skip dumping tnc tree when zroot is null

2025-02-21T12:49:21+00:00

[ Upstream commit bdb0ca39e0acccf6771db49c3f94ed787d05f2d7 ] Clearing slab cache will free all znode in memory and make c->zroot.znode = NULL, then dumping tnc tree will access c->zroot.znode which cause null pointer dereference. Link: https://bugzilla.kernel.org/show_bug.cgi?id=219624#c0 Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: pangliyuan Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubifs: authentication: Fix use-after-free in ubifs_tnc_end_commit

2024-12-14T18:54:08+00:00

[ Upstream commit 4617fb8fc15effe8eda4dd898d4e33eb537a7140 ] After an insertion in TNC, the tree might split and cause a node to change its `znode->parent`. A further deletion of other nodes in the tree (which also could free the nodes), the aforementioned node's `znode->cparent` could still point to a freed node. This `znode->cparent` may not be updated when getting nodes to commit in `ubifs_tnc_start_commit()`. This could then trigger a use-after-free when accessing the `znode->cparent` in `write_index()` in `ubifs_tnc_end_commit()`. This can be triggered by running rm -f /etc/test-file.bin dd if=/dev/urandom of=/etc/test-file.bin bs=1M count=60 conv=fsync in a loop, and with `CONFIG_UBIFS_FS_AUTHENTICATION`. KASAN then reports: BUG: KASAN: use-after-free in ubifs_tnc_end_commit+0xa5c/0x1950 Write of size 32 at addr ffffff800a3af86c by task ubifs_bgt0_20/153 Call trace: dump_backtrace+0x0/0x340 show_stack+0x18/0x24 dump_stack_lvl+0x9c/0xbc print_address_description.constprop.0+0x74/0x2b0 kasan_report+0x1d8/0x1f0 kasan_check_range+0xf8/0x1a0 memcpy+0x84/0xf4 ubifs_tnc_end_commit+0xa5c/0x1950 do_commit+0x4e0/0x1340 ubifs_bg_thread+0x234/0x2e0 kthread+0x36c/0x410 ret_from_fork+0x10/0x20 Allocated by task 401: kasan_save_stack+0x38/0x70 __kasan_kmalloc+0x8c/0xd0 __kmalloc+0x34c/0x5bc tnc_insert+0x140/0x16a4 ubifs_tnc_add+0x370/0x52c ubifs_jnl_write_data+0x5d8/0x870 do_writepage+0x36c/0x510 ubifs_writepage+0x190/0x4dc __writepage+0x58/0x154 write_cache_pages+0x394/0x830 do_writepages+0x1f0/0x5b0 filemap_fdatawrite_wbc+0x170/0x25c file_write_and_wait_range+0x140/0x190 ubifs_fsync+0xe8/0x290 vfs_fsync_range+0xc0/0x1e4 do_fsync+0x40/0x90 __arm64_sys_fsync+0x34/0x50 invoke_syscall.constprop.0+0xa8/0x260 do_el0_svc+0xc8/0x1f0 el0_svc+0x34/0x70 el0t_64_sync_handler+0x108/0x114 el0t_64_sync+0x1a4/0x1a8 Freed by task 403: kasan_save_stack+0x38/0x70 kasan_set_track+0x28/0x40 kasan_set_free_info+0x28/0x4c __kasan_slab_free+0xd4/0x13c kfree+0xc4/0x3a0 tnc_delete+0x3f4/0xe40 ubifs_tnc_remove_range+0x368/0x73c ubifs_tnc_remove_ino+0x29c/0x2e0 ubifs_jnl_delete_inode+0x150/0x260 ubifs_evict_inode+0x1d4/0x2e4 evict+0x1c8/0x450 iput+0x2a0/0x3c4 do_unlinkat+0x2cc/0x490 __arm64_sys_unlinkat+0x90/0x100 invoke_syscall.constprop.0+0xa8/0x260 do_el0_svc+0xc8/0x1f0 el0_svc+0x34/0x70 el0t_64_sync_handler+0x108/0x114 el0t_64_sync+0x1a4/0x1a8 The offending `memcpy()` in `ubifs_copy_hash()` has a use-after-free when a node becomes root in TNC but still has a `cparent` to an already freed node. More specifically, consider the following TNC: zroot / / zp1 / / zn Inserting a new node `zn_new` with a key smaller then `zn` will trigger a split in `tnc_insert()` if `zp1` is full: zroot / \ / \ zp1 zp2 / \ / \ zn_new zn `zn->parent` has now been moved to `zp2`, *but* `zn->cparent` still points to `zp1`. Now, consider a removal of all the nodes _except_ `zn`. Just when `tnc_delete()` is about to delete `zroot` and `zp2`: zroot \ \ zp2 \ \ zn `zroot` and `zp2` get freed and the tree collapses: zn `zn` now becomes the new `zroot`. `get_znodes_to_commit()` will now only find `zn`, the new `zroot`, and `write_index()` will check its `znode->cparent` that wrongly points to the already freed `zp1`. `ubifs_copy_hash()` thus gets wrongly called with `znode->cparent->zbranch[znode->iip].hash` that triggers the use-after-free! Fix this by explicitly setting `znode->cparent` to `NULL` in `get_znodes_to_commit()` for the root node. The search for the dirty nodes is bottom-up in the tree. Thus, when `find_next_dirty(znode)` returns NULL, the current `znode` _is_ the root node. Add an assert for this. Fixes: 16a26b20d2af ("ubifs: authentication: Add hashes to index nodes") Tested-by: Waqar Hameed Co-developed-by: Zhihao Cheng Signed-off-by: Zhihao Cheng Signed-off-by: Waqar Hameed Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubifs: Correct the total block count by deducting journal reservation

2024-12-14T18:54:07+00:00

[ Upstream commit 84a2bee9c49769310efa19601157ef50a1df1267 ] Since commit e874dcde1cbf ("ubifs: Reserve one leb for each journal head while doing budget"), available space is calulated by deducting reservation for all journal heads. However, the total block count ( which is only used by statfs) is not updated yet, which will cause the wrong displaying for used space(total - available). Fix it by deducting reservation for all journal heads from total block count. Fixes: e874dcde1cbf ("ubifs: Reserve one leb for each journal head while doing budget") Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubifs: Set page uptodate in the correct place

2024-04-03T13:19:27+00:00

[ Upstream commit 723012cab779eee8228376754e22c6594229bf8f ] Page cache reads are lockless, so setting the freshly allocated page uptodate before we've overwritten it with the data it's supposed to have in it will allow a simultaneous reader to see old data. Move the call to SetPageUptodate into ubifs_write_end(), which is after we copied the new data into the page. Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubifs: ubifs_symlink: Fix memleak of inode->i_link in error path

2024-02-01T00:17:02+00:00

commit 1e022216dcd248326a5bb95609d12a6815bca4e2 upstream. For error handling path in ubifs_symlink(), inode will be marked as bad first, then iput() is invoked. If inode->i_link is initialized by fscrypt_encrypt_symlink() in encryption scenario, inode->i_link won't be freed by callchain ubifs_free_inode -> fscrypt_free_inode in error handling path, because make_bad_inode() has changed 'inode->i_mode' as 'S_IFREG'. Following kmemleak is easy to be reproduced by injecting error in ubifs_jnl_update() when doing symlink in encryption scenario: unreferenced object 0xffff888103da3d98 (size 8): comm "ln", pid 1692, jiffies 4294914701 (age 12.045s) backtrace: kmemdup+0x32/0x70 __fscrypt_encrypt_symlink+0xed/0x1c0 ubifs_symlink+0x210/0x300 [ubifs] vfs_symlink+0x216/0x360 do_symlinkat+0x11a/0x190 do_syscall_64+0x3b/0xe0 There are two ways fixing it: 1. Remove make_bad_inode() in error handling path. We can do that because ubifs_evict_inode() will do same processes for good symlink inode and bad symlink inode, for inode->i_nlink checking is before is_bad_inode(). 2. Free inode->i_link before marking inode bad. Method 2 is picked, it has less influence, personally, I think. Cc: stable@vger.kernel.org Fixes: 2c58d548f570 ("fscrypt: cache decrypted symlink target in ->i_link") Signed-off-by: Zhihao Cheng Suggested-by: Eric Biggers Reviewed-by: Eric Biggers Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

ubifs: fix possible dereference after free

2024-01-01T12:39:06+00:00

[ Upstream commit d81efd66106c03771ffc8637855a6ec24caa6350 ] 'old_idx' could be dereferenced after free via 'rb_link_node' function call. Fixes: b5fda08ef213 ("ubifs: Fix memleak when insert_old_idx() failed") Co-developed-by: Ivanov Mikhail Signed-off-by: Konstantin Meskhidze Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubifs: Fix memory leak in do_rename

2023-05-11T14:03:05+00:00

commit 3a36d20e012903f45714df2731261fdefac900cb upstream. If renaming a file in an encrypted directory, function fscrypt_setup_filename allocates memory for a file name. This name is never used, and before returning to the caller the memory for it is not freed. When running kmemleak on it we see that it is registered as a leak. The report below is triggered by a simple program 'rename' that renames a file in an encrypted directory: unreferenced object 0xffff888101502840 (size 32): comm "rename", pid 9404, jiffies 4302582475 (age 435.735s) backtrace: __kmem_cache_alloc_node __kmalloc fscrypt_setup_filename do_rename ubifs_rename vfs_rename do_renameat2 To fix this we can remove the call to fscrypt_setup_filename as it's not needed. Fixes: 278d9a243635f26 ("ubifs: Rename whiteout atomically") Reported-by: Zhihao Cheng Signed-off-by: Mårten Lindahl Reviewed-by: Zhihao Cheng Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

ubifs: Free memory for tmpfile name

2023-05-11T14:03:05+00:00

commit 1fb815b38bb31d6af9bd0540b8652a0d6fe6cfd3 upstream. When opening a ubifs tmpfile on an encrypted directory, function fscrypt_setup_filename allocates memory for the name that is to be stored in the directory entry, but after the name has been copied to the directory entry inode, the memory is not freed. When running kmemleak on it we see that it is registered as a leak. The report below is triggered by a simple program 'tmpfile' just opening a tmpfile: unreferenced object 0xffff88810178f380 (size 32): comm "tmpfile", pid 509, jiffies 4294934744 (age 1524.742s) backtrace: __kmem_cache_alloc_node __kmalloc fscrypt_setup_filename ubifs_tmpfile vfs_tmpfile path_openat Free this memory after it has been copied to the inode. Signed-off-by: Mårten Lindahl Reviewed-by: Zhihao Cheng Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

ubifs: Fix memleak when insert_old_idx() failed

2023-05-11T14:03:05+00:00

commit b5fda08ef213352ac2df7447611eb4d383cce929 upstream. Following process will cause a memleak for copied up znode: dirty_cow_znode zn = copy_znode(c, znode); err = insert_old_idx(c, zbr->lnum, zbr->offs); if (unlikely(err)) return ERR_PTR(err); // No one refers to zn. Fetch a reproducer in [Link]. Function copy_znode() is split into 2 parts: resource allocation and znode replacement, insert_old_idx() is split in similar way, so resource cleanup could be done in error handling path without corrupting metadata(mem & disk). It's okay that old index inserting is put behind of add_idx_dirt(), old index is used in layout_leb_in_gaps(), so the two processes do not depend on each other. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216705 Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Cc: stable@vger.kernel.org Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

Revert "ubifs: dirty_cow_znode: Fix memleak in error handling path"

2023-05-11T14:03:04+00:00

commit 7d01cb27f6aebc54efbe28d8961a973b8f795b13 upstream. This reverts commit 122deabfe1428 (ubifs: dirty_cow_znode: Fix memleak in error handling path). After commit 122deabfe1428 applied, if insert_old_idx() failed, old index neither exists in TNC nor in old-index tree. Which means that old index node could be overwritten in layout_leb_in_gaps(), then ubifs image will be corrupted in power-cut. Fixes: 122deabfe1428 (ubifs: dirty_cow_znode: Fix memleak ... path) Cc: stable@vger.kernel.org Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman