ce6dede912
[syzbot reported] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 5061 Comm: syz-executor404 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:dtInsertEntry+0xd0c/0x1780 fs/jfs/jfs_dtree.c:3713 ... [Analyze] In dtInsertEntry(), when the pointer h has the same value as p, after writing name in UniStrncpy_to_le(), p->header.flag will be cleared. This will cause the previously true judgment "p->header.flag & BT-LEAF" to change to no after writing the name operation, this leads to entering an incorrect branch and accessing the uninitialized object ih when judging this condition for the second time. [Fix] After got the page, check freelist first, if freelist == 0 then exit dtInsert() and return -EINVAL. Reported-by: syzbot+bba84aef3a26fb93deb9@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis <eadavis@qq.com> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.