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path: root/fs/jffs2/read.c
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2009-11-30jffs2: Fix memory corruption in jffs2_read_inode_range()David Woodhouse
In 2.6.23 kernel, commit a32ea1e1f925399e0d81ca3f7394a44a6dafa12c ("Fix read/truncate race") fixed a race in the generic code, and as a side effect, now do_generic_file_read() can ask us to readpage() past the i_size. This seems to be correctly handled by the block routines (e.g. block_read_full_page() fills the page with zeroes in case if somebody is trying to read past the last inode's block). JFFS2 doesn't handle this; it assumes that it won't be asked to read pages which don't exist -- and thus that there will be at least _one_ valid 'frag' on the page it's being asked to read. It will fill any holes with the following memset: memset(buf, 0, min(end, frag->ofs + frag->size) - offset); When the 'closest smaller match' returned by jffs2_lookup_node_frag() is actually on a previous page and ends before 'offset', that results in: memset(buf, 0, <huge unsigned negative>); Hopefully, in most cases the corruption is fatal, and quickly causing random oopses, like this: root@10.0.0.4:~/ltp-fs-20090531# ./testcases/kernel/fs/ftest/ftest01 Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc01cd980 Oops: Kernel access of bad area, sig: 11 [#1] [...] NIP [c01cd980] rb_insert_color+0x38/0x184 LR [c0043978] enqueue_hrtimer+0x88/0xc4 Call Trace: [c6c63b60] [c004f9a8] tick_sched_timer+0xa0/0xe4 (unreliable) [c6c63b80] [c0043978] enqueue_hrtimer+0x88/0xc4 [c6c63b90] [c0043a48] __run_hrtimer+0x94/0xbc [c6c63bb0] [c0044628] hrtimer_interrupt+0x140/0x2b8 [c6c63c10] [c000f8e8] timer_interrupt+0x13c/0x254 [c6c63c30] [c001352c] ret_from_except+0x0/0x14 --- Exception: 901 at memset+0x38/0x5c LR = jffs2_read_inode_range+0x144/0x17c [c6c63cf0] [00000000] (null) (unreliable) This patch fixes the issue, plus fixes all LTP tests on NAND/UBI with JFFS2 filesystem that were failing since 2.6.23 (seems like the bug above also broke the truncation). Reported-By: Anton Vorontsov <avorontsov@ru.mvista.com> Tested-By: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-25[JFFS2] Tidy up licensing/copyright boilerplate.David Woodhouse
In particular, remove the bit in the LICENCE file about contacting Red Hat for alternative arrangements. Their errant IS department broke that arrangement a long time ago -- the policy of collecting copyright assignments from contributors came to an end when the plug was pulled on the servers hosting the project, without notice or reason. We do still dual-license it for use with eCos, with the GPL+exception licence approved by the FSF as being GPL-compatible. It's just that nobody has the right to license it differently. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-11-07[JFFS2] Clean up trailing white spacesThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2005-11-06[JFFS2] Debug code clean up - step 3Artem B. Bityutskiy
Various simplifiactions. printk format corrections. Convert more code to use the new debug functions. Signed-off-by: Artem B. Bityutskiy <dedekind@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2005-11-06[JFFS2] Debug code clean up - step 1Artem B. Bityutskiy
Move debug functions into a seperate source file Signed-off-by: Artem B. Bityutskiy <dedekind@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2005-05-23[JFFS2] Add symlink caching support.Artem B. Bityuckiy
Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!