kernel/linux.git/fs/jffs2/scan.c, branch v6.19.11

jffs2: check jffs2_prealloc_raw_node_refs() result in few other places

2025-05-22T18:54:38+00:00

Fuzzing hit another invalid pointer dereference due to the lack of checking whether jffs2_prealloc_raw_node_refs() completed successfully. Subsequent logic implies that the node refs have been allocated. Handle that. The code is ready for propagating the error upwards. KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 5835 Comm: syz-executor145 Not tainted 5.10.234-syzkaller #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:jffs2_link_node_ref+0xac/0x690 fs/jffs2/nodelist.c:600 Call Trace: jffs2_mark_erased_block fs/jffs2/erase.c:460 [inline] jffs2_erase_pending_blocks+0x688/0x1860 fs/jffs2/erase.c:118 jffs2_garbage_collect_pass+0x638/0x1a00 fs/jffs2/gc.c:253 jffs2_reserve_space+0x3f4/0xad0 fs/jffs2/nodemgmt.c:167 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362 jffs2_write_end+0x712/0x1110 fs/jffs2/file.c:302 generic_perform_write+0x2c2/0x500 mm/filemap.c:3347 __generic_file_write_iter+0x252/0x610 mm/filemap.c:3465 generic_file_write_iter+0xdb/0x230 mm/filemap.c:3497 call_write_iter include/linux/fs.h:2039 [inline] do_iter_readv_writev+0x46d/0x750 fs/read_write.c:740 do_iter_write+0x18c/0x710 fs/read_write.c:866 vfs_writev+0x1db/0x6a0 fs/read_write.c:939 do_pwritev fs/read_write.c:1036 [inline] __do_sys_pwritev fs/read_write.c:1083 [inline] __se_sys_pwritev fs/read_write.c:1078 [inline] __x64_sys_pwritev+0x235/0x310 fs/read_write.c:1078 do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 2f785402f39b ("[JFFS2] Reduce visibility of raw_node_ref to upper layers of JFFS2 code.") Fixes: f560928baa60 ("[JFFS2] Allocate node_ref for wasted space when skipping to page boundary") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

jffs2: fix memory leak in jffs2_scan_medium

2022-03-16T21:54:03+00:00

If an error is returned in jffs2_scan_eraseblock() and some memory has been added to the jffs2_summary *s, we can observe the following kmemleak report: -------------------------------------------- unreferenced object 0xffff88812b889c40 (size 64): comm "mount", pid 692, jiffies 4294838325 (age 34.288s) hex dump (first 32 bytes): 40 48 b5 14 81 88 ff ff 01 e0 31 00 00 00 50 00 @H........1...P. 00 00 01 00 00 00 01 00 00 00 02 00 00 00 09 08 ................ backtrace: [] __kmalloc+0x613/0x910 [] jffs2_sum_add_dirent_mem+0x5c/0xa0 [] jffs2_scan_medium.cold+0x36e5/0x4794 [] jffs2_do_mount_fs.cold+0xa7/0x2267 [] jffs2_do_fill_super+0x383/0xc30 [] jffs2_fill_super+0x2ea/0x4c0 [] mtd_get_sb+0x254/0x400 [] mtd_get_sb_by_nr+0x4f/0xd0 [] get_tree_mtd+0x498/0x840 [] jffs2_get_tree+0x25/0x30 [] vfs_get_tree+0x8d/0x2e0 [] path_mount+0x50f/0x1e50 [] do_mount+0x107/0x130 [] __se_sys_mount+0x1c5/0x2f0 [] __x64_sys_mount+0xc7/0x160 [] do_syscall_64+0x45/0x70 unreferenced object 0xffff888114b54840 (size 32): comm "mount", pid 692, jiffies 4294838325 (age 34.288s) hex dump (first 32 bytes): c0 75 b5 14 81 88 ff ff 02 e0 02 00 00 00 02 00 .u.............. 00 00 84 00 00 00 44 00 00 00 6b 6b 6b 6b 6b a5 ......D...kkkkk. backtrace: [] kmem_cache_alloc_trace+0x584/0x880 [] jffs2_sum_add_inode_mem+0x54/0x90 [] jffs2_scan_medium.cold+0x4481/0x4794 [...] unreferenced object 0xffff888114b57280 (size 32): comm "mount", pid 692, jiffies 4294838393 (age 34.357s) hex dump (first 32 bytes): 10 d5 6c 11 81 88 ff ff 08 e0 05 00 00 00 01 00 ..l............. 00 00 38 02 00 00 28 00 00 00 6b 6b 6b 6b 6b a5 ..8...(...kkkkk. backtrace: [] kmem_cache_alloc_trace+0x584/0x880 [] jffs2_sum_add_xattr_mem+0x54/0x90 [] jffs2_scan_medium.cold+0x298c/0x4794 [...] unreferenced object 0xffff8881116cd510 (size 16): comm "mount", pid 692, jiffies 4294838395 (age 34.355s) hex dump (first 16 bytes): 00 00 00 00 00 00 00 00 09 e0 60 02 00 00 6b a5 ..........`...k. backtrace: [] kmem_cache_alloc_trace+0x584/0x880 [] jffs2_sum_add_xref_mem+0x54/0x90 [] jffs2_scan_medium.cold+0x3a20/0x4794 [...] -------------------------------------------- Therefore, we should call jffs2_sum_reset_collected(s) on exit to release the memory added in s. In addition, a new tag "out_buf" is added to prevent the NULL pointer reference caused by s being NULL. (thanks to Zhang Yi for this analysis) Fixes: e631ddba5887 ("[JFFS2] Add erase block summary support (mount time improvement)") Cc: stable@vger.kernel.org Co-developed-with: Zhihao Cheng Signed-off-by: Baokun Li Signed-off-by: Richard Weinberger

jffs2: Fix kasan slab-out-of-bounds problem

2021-04-15T20:00:46+00:00

KASAN report a slab-out-of-bounds problem. The logs are listed below. It is because in function jffs2_scan_dirent_node, we alloc "checkedlen+1" bytes for fd->name and we check crc with length rd->nsize. If checkedlen is less than rd->nsize, it will cause the slab-out-of-bounds problem. jffs2: Dirent at *** has zeroes in name. Truncating to %d char ================================================================== BUG: KASAN: slab-out-of-bounds in crc32_le+0x1ce/0x260 at addr ffff8800842cf2d1 Read of size 1 by task test_JFFS2/915 ============================================================================= BUG kmalloc-64 (Tainted: G B O ): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in jffs2_alloc_full_dirent+0x2a/0x40 age=0 cpu=1 pid=915 ___slab_alloc+0x580/0x5f0 __slab_alloc.isra.24+0x4e/0x64 __kmalloc+0x170/0x300 jffs2_alloc_full_dirent+0x2a/0x40 jffs2_scan_eraseblock+0x1ca4/0x3b64 jffs2_scan_medium+0x285/0xfe0 jffs2_do_mount_fs+0x5fb/0x1bbc jffs2_do_fill_super+0x245/0x6f0 jffs2_fill_super+0x287/0x2e0 mount_mtd_aux.isra.0+0x9a/0x144 mount_mtd+0x222/0x2f0 jffs2_mount+0x41/0x60 mount_fs+0x63/0x230 vfs_kern_mount.part.6+0x6c/0x1f4 do_mount+0xae8/0x1940 SyS_mount+0x105/0x1d0 INFO: Freed in jffs2_free_full_dirent+0x22/0x40 age=27 cpu=1 pid=915 __slab_free+0x372/0x4e4 kfree+0x1d4/0x20c jffs2_free_full_dirent+0x22/0x40 jffs2_build_remove_unlinked_inode+0x17a/0x1e4 jffs2_do_mount_fs+0x1646/0x1bbc jffs2_do_fill_super+0x245/0x6f0 jffs2_fill_super+0x287/0x2e0 mount_mtd_aux.isra.0+0x9a/0x144 mount_mtd+0x222/0x2f0 jffs2_mount+0x41/0x60 mount_fs+0x63/0x230 vfs_kern_mount.part.6+0x6c/0x1f4 do_mount+0xae8/0x1940 SyS_mount+0x105/0x1d0 entry_SYSCALL_64_fastpath+0x1e/0x97 Call Trace: [] dump_stack+0x59/0x7e [] print_trailer+0x125/0x1b0 [] object_err+0x34/0x40 [] kasan_report.part.1+0x21f/0x534 [] ? vprintk+0x2d/0x40 [] ? crc32_le+0x1ce/0x260 [] kasan_report+0x26/0x30 [] __asan_load1+0x3d/0x50 [] crc32_le+0x1ce/0x260 [] ? jffs2_alloc_full_dirent+0x2a/0x40 [] jffs2_scan_eraseblock+0x1d0c/0x3b64 [] ? jffs2_scan_medium+0xccf/0xfe0 [] ? jffs2_scan_make_ino_cache+0x14c/0x14c [] ? kasan_unpoison_shadow+0x35/0x50 [] ? kasan_unpoison_shadow+0x35/0x50 [] ? kasan_kmalloc+0x5e/0x70 [] ? kmem_cache_alloc_trace+0x10c/0x2cc [] ? mtd_point+0xf7/0x130 [] jffs2_scan_medium+0x285/0xfe0 [] ? jffs2_scan_eraseblock+0x3b64/0x3b64 [] ? kasan_unpoison_shadow+0x35/0x50 [] ? kasan_unpoison_shadow+0x35/0x50 [] ? kasan_kmalloc+0x5e/0x70 [] ? __kmalloc+0x12b/0x300 [] ? kasan_kmalloc+0x5e/0x70 [] ? jffs2_sum_init+0x9f/0x240 [] jffs2_do_mount_fs+0x5fb/0x1bbc [] ? jffs2_del_noinode_dirent+0x640/0x640 [] ? kasan_kmalloc+0x5e/0x70 [] ? __init_rwsem+0x97/0xac [] jffs2_do_fill_super+0x245/0x6f0 [] jffs2_fill_super+0x287/0x2e0 [] ? jffs2_parse_options+0x594/0x594 [] mount_mtd_aux.isra.0+0x9a/0x144 [] mount_mtd+0x222/0x2f0 [] ? jffs2_parse_options+0x594/0x594 [] ? mount_mtd_aux.isra.0+0x144/0x144 [] ? free_pages+0x13/0x1c [] ? selinux_sb_copy_data+0x278/0x2e0 [] jffs2_mount+0x41/0x60 [] mount_fs+0x63/0x230 [] ? alloc_vfsmnt+0x32f/0x3b0 [] vfs_kern_mount.part.6+0x6c/0x1f4 [] do_mount+0xae8/0x1940 [] ? audit_filter_rules.constprop.6+0x1d10/0x1d10 [] ? copy_mount_string+0x40/0x40 [] ? alloc_pages_current+0xa4/0x1bc [] ? __get_free_pages+0x25/0x50 [] ? copy_mount_options.part.17+0x183/0x264 [] SyS_mount+0x105/0x1d0 [] ? copy_mnt_ns+0x560/0x560 [] ? msa_space_switch_handler+0x13d/0x190 [] entry_SYSCALL_64_fastpath+0x1e/0x97 [] ? msa_space_switch+0xb0/0xe0 Memory state around the buggy address: ffff8800842cf180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8800842cf200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8800842cf280: fc fc fc fc fc fc 00 00 00 00 01 fc fc fc fc fc ^ ffff8800842cf300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8800842cf380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Cc: stable@vger.kernel.org Reported-by: Kunkun Xu Signed-off-by: lizhe Signed-off-by: Richard Weinberger

jffs2: fix jffs2 mounting failure

2020-08-02T21:56:13+00:00

Thanks for the advice mentioned in the email. This is my v3 patch for this problem. Mounting jffs2 on nand flash will get message "failed: I/O error" with the steps listed below. 1.umount jffs2 2.erase nand flash 3.mount jffs2 on it (this mounting operation will be successful) 4.do chown or chmod to the mount point directory 5.umount jffs2 6.mount jffs2 on nand flash After step 6, we will get message "mount ... failed: I/O error". Typical image of this problem is like: Empty space found from 0x00000000 to 0x008a0000 Inode node at xx, totlen 0x00000044, #ino 1, version 1, isize 0... The reason for this mounting failure is that at the end of function jffs2_scan_medium(), jffs2 will check the used_size and some info of nr_blocks.If conditions are met, it will return -EIO. The detail is that, in the steps listed above, step 4 will write jffs2_raw_inode into flash without jffs2_raw_dirent, which will cause that there are some jffs2_raw_inode but no jffs2_raw_dirent on flash. This will meet the condition at the end of function jffs2_scan_medium() and return -EIO if we umount jffs2 and mount it again. We notice that jffs2 add the value of c->unchecked_size if we find an inode node while mounting. And jffs2 will never add the value of c->unchecked_size in other situations. So this patch add one more condition about c->unchecked_size of the judgement to fix this problem. Signed-off-by: Zhe Li Signed-off-by: Richard Weinberger

jffs2: Fix memory leak in jffs2_scan_eraseblock() error path

2019-09-15T20:42:41+00:00

In jffs2_scan_eraseblock(), 'sumptr' is allocated through kmalloc() if 'sumlen' is larger than 'buf_size'. However, it is not deallocated in the following execution if jffs2_fill_scan_buf() fails, leading to a memory leak bug. To fix this issue, free 'sumptr' before returning the error. Signed-off-by: Wenwen Wang Signed-off-by: Richard Weinberger

vfs: make the string hashes salt the hash

2016-06-11T03:21:46+00:00

We always mixed in the parent pointer into the dentry name hash, but we did it late at lookup time. It turns out that we can simplify that lookup-time action by salting the hash with the parent pointer early instead of late. A few other users of our string hashes also wanted to mix in their own pointers into the hash, and those are updated to use the same mechanism. Hash users that don't have any particular initial salt can just use the NULL pointer as a no-salt. Cc: Vegard Nossum Cc: George Spelvin Cc: Al Viro Signed-off-by: Linus Torvalds

jffs2: fix handling of corrupted summary length

2015-02-13T17:07:54+00:00

sm->offset maybe wrong but magic maybe right, the offset do not have CRC. Badness at c00c7580 [verbose debug info unavailable] NIP: c00c7580 LR: c00c718c CTR: 00000014 REGS: df07bb40 TRAP: 0700 Not tainted (2.6.34.13-WR4.3.0.0_standard) MSR: 00029000 CR: 22084f84 XER: 00000000 TASK = df84d6e0[908] 'mount' THREAD: df07a000 GPR00: 00000001 df07bbf0 df84d6e0 00000000 00000001 00000000 df07bb58 00000041 GPR08: 00000041 c0638860 00000000 00000010 22084f88 100636c8 df814ff8 00000000 GPR16: df84d6e0 dfa558cc c05adb90 00000048 c0452d30 00000000 000240d0 000040d0 GPR24: 00000014 c05ae734 c05be2e0 00000000 00000001 00000000 00000000 c05ae730 NIP [c00c7580] __alloc_pages_nodemask+0x4d0/0x638 LR [c00c718c] __alloc_pages_nodemask+0xdc/0x638 Call Trace: [df07bbf0] [c00c718c] __alloc_pages_nodemask+0xdc/0x638 (unreliable) [df07bc90] [c00c7708] __get_free_pages+0x20/0x48 [df07bca0] [c00f4a40] __kmalloc+0x15c/0x1ec [df07bcd0] [c01fc880] jffs2_scan_medium+0xa58/0x14d0 [df07bd70] [c01ff38c] jffs2_do_mount_fs+0x1f4/0x6b4 [df07bdb0] [c020144c] jffs2_do_fill_super+0xa8/0x260 [df07bdd0] [c020230c] jffs2_fill_super+0x104/0x184 [df07be00] [c0335814] get_sb_mtd_aux+0x9c/0xec [df07be20] [c033596c] get_sb_mtd+0x84/0x1e8 [df07be60] [c0201ed0] jffs2_get_sb+0x1c/0x2c [df07be70] [c0103898] vfs_kern_mount+0x78/0x1e8 [df07bea0] [c0103a58] do_kern_mount+0x40/0x100 [df07bec0] [c011fe90] do_mount+0x240/0x890 [df07bf10] [c0120570] sys_mount+0x90/0xd8 [df07bf40] [c00110d8] ret_from_syscall+0x0/0x4 === Exception: c01 at 0xff61a34 LR = 0x100135f0 Instruction dump: 38800005 38600000 48010f41 4bfffe1c 4bfc2d15 4bfffe8c 72e90200 4082fc28 3d20c064 39298860 8809000d 68000001 <0f000000> 2f800000 419efc0c 38000001 mount: mounting /dev/mtdblock3 on /common failed: Input/output error Signed-off-by: Chen Jie Cc: Signed-off-by: Andrew Morton Signed-off-by: David Woodhouse

jffs2: Use pr_fmt and remove jffs: from formats

2012-03-26T23:40:19+00:00

Use pr_fmt to prefix KBUILD_MODNAME to appropriate logging messages. Remove now unnecessary internal prefixes from formats. Signed-off-by: Joe Perches Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse

jffs2: Convert printks to pr_

2012-03-26T23:39:40+00:00

Use the more current logging style. Coalesce formats, align arguments. Convert uses of embedded function names to %s, __func__. A couple of long line checkpatch errors I don't care about exist. Signed-off-by: Joe Perches Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse

jffs2: Convert most D1/D2 macros to jffs2_dbg

2012-03-26T23:39:24+00:00

D1 and D2 macros are mostly uses to emit debugging messages. Convert the logging uses of D1 & D2 to jffs2_dbg(level, fmt, ...) to be a bit more consistent style with the rest of the kernel. All jffs2_dbg output is now at KERN_DEBUG where some of the previous uses were emitted at various KERN_s. Signed-off-by: Joe Perches Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse