kernel/linux.git/fs/jffs2/summary.c, branch v6.12.80

jffs2: check that raw node were preallocated before writing summary

2025-06-27T10:11:37+00:00

commit ec9e6f22bce433b260ea226de127ec68042849b0 upstream. Syzkaller detected a kernel bug in jffs2_link_node_ref, caused by fault injection in jffs2_prealloc_raw_node_refs. jffs2_sum_write_sumnode doesn't check return value of jffs2_prealloc_raw_node_refs and simply lets any error propagate into jffs2_sum_write_data, which eventually calls jffs2_link_node_ref in order to link the summary to an expectedly allocated node. kernel BUG at fs/jffs2/nodelist.c:592! invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 PID: 31277 Comm: syz-executor.7 Not tainted 6.1.128-syzkaller-00139-ge10f83ca10a1 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:jffs2_link_node_ref+0x570/0x690 fs/jffs2/nodelist.c:592 Call Trace: jffs2_sum_write_data fs/jffs2/summary.c:841 [inline] jffs2_sum_write_sumnode+0xd1a/0x1da0 fs/jffs2/summary.c:874 jffs2_do_reserve_space+0xa18/0xd60 fs/jffs2/nodemgmt.c:388 jffs2_reserve_space+0x55f/0xaa0 fs/jffs2/nodemgmt.c:197 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362 jffs2_write_end+0x726/0x15d0 fs/jffs2/file.c:301 generic_perform_write+0x314/0x5d0 mm/filemap.c:3856 __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3973 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4005 call_write_iter include/linux/fs.h:2265 [inline] do_iter_readv_writev+0x20f/0x3c0 fs/read_write.c:735 do_iter_write+0x186/0x710 fs/read_write.c:861 vfs_iter_write+0x70/0xa0 fs/read_write.c:902 iter_file_splice_write+0x73b/0xc90 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0x10c/0x170 fs/splice.c:950 splice_direct_to_actor+0x337/0xa10 fs/splice.c:896 do_splice_direct+0x1a9/0x280 fs/splice.c:1002 do_sendfile+0xb13/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Fix this issue by checking return value of jffs2_prealloc_raw_node_refs before calling jffs2_sum_write_data. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Cc: stable@vger.kernel.org Fixes: 2f785402f39b ("[JFFS2] Reduce visibility of raw_node_ref to upper layers of JFFS2 code.") Signed-off-by: Artem Sadovnikov Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

jffs2: fix use after free in jffs2_sum_write_data()

2021-02-12T20:53:22+00:00

clang static analysis reports this problem fs/jffs2/summary.c:794:31: warning: Use of memory after it is freed c->summary->sum_list_head = temp->u.next; ^~~~~~~~~~~~ In jffs2_sum_write_data(), in a loop summary data is handles a node at a time. When it has written out the node it is removed the summary list, and the node is deleted. In the corner case when a JFFS2_FEATURE_RWCOMPAT_COPY is seen, a call is made to jffs2_sum_disable_collecting(). jffs2_sum_disable_collecting() deletes the whole list which conflicts with the loop's deleting the list by parts. To preserve the old behavior of stopping the write midway, bail out of the loop after disabling summary collection. Fixes: 6171586a7ae5 ("[JFFS2] Correct handling of JFFS2_FEATURE_RWCOMPAT_COPY nodes.") Signed-off-by: Tom Rix Reviewed-by: Nathan Chancellor 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 sparse warning: unexpected unlock

2014-10-22T08:35:41+00:00

fs/jffs2/summary.c:846:5: warning: context imbalance in 'jffs2_sum_write_sumnode' - unexpected unlock Suggested-by: Brian Norris Suggested-by: Josh Triplett Signed-off-by: Fabian Frederick Reviewed-by: Josh Triplett Signed-off-by: Brian Norris

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

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi

JFFS2: fix min/max confusion

2009-11-30T09:59:48+00:00

MAX_SUMMARY_SIZE was meant as a limit, not as a minimum Signed-off-by: Roel Kluin Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse

[JFFS2] Fix allocation of summary buffer

2008-08-01T09:07:51+00:00

We can't use vmalloc for the buffer we use for writing summaries, because some drivers may want to DMA from it. So limit the size to 64KiB and use kmalloc for it instead. Signed-off-by: David Woodhouse

[JFFS2] Handle dirents on the flash with embedded zero bytes in names.

2007-10-13T10:35:58+00:00

In three places: summary scan, normal scan, REF_PRISTINE GC. Just truncate at the NUL, since that was the correct thing to do in the only case where this (inexplicable) breakage has been seen. Signed-off-by: David Woodhouse