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| author | Zixuan Fu <r33s3n6@gmail.com> | 2022-04-11 12:45:34 +0200 |
|---|---|---|
| committer | Dave Kleikamp <dave.kleikamp@oracle.com> | 2022-04-19 17:20:51 +0200 |
| commit | 0d4837fdb796f99369cf7691d33de1b856bcaf1f (patch) | |
| tree | f6ca163b2a14ed2e152cf70458b1da8a125acecc /fs/jfs | |
| parent | Linux 5.18-rc3 (diff) | |
| download | linux-0d4837fdb796f99369cf7691d33de1b856bcaf1f.tar.xz linux-0d4837fdb796f99369cf7691d33de1b856bcaf1f.zip | |
fs: jfs: fix possible NULL pointer dereference in dbFree()
In our fault-injection testing, the variable "nblocks" in dbFree() can be
zero when kmalloc_array() fails in dtSearch(). In this case, the variable
"mp" in dbFree() would be NULL and then it is dereferenced in
"write_metapage(mp)".
The failure log is listed as follows:
[ 13.824137] BUG: kernel NULL pointer dereference, address: 0000000000000020
...
[ 13.827416] RIP: 0010:dbFree+0x5f7/0x910 [jfs]
[ 13.834341] Call Trace:
[ 13.834540] <TASK>
[ 13.834713] txFreeMap+0x7b4/0xb10 [jfs]
[ 13.835038] txUpdateMap+0x311/0x650 [jfs]
[ 13.835375] jfs_lazycommit+0x5f2/0xc70 [jfs]
[ 13.835726] ? sched_dynamic_update+0x1b0/0x1b0
[ 13.836092] kthread+0x3c2/0x4a0
[ 13.836355] ? txLockFree+0x160/0x160 [jfs]
[ 13.836763] ? kthread_unuse_mm+0x160/0x160
[ 13.837106] ret_from_fork+0x1f/0x30
[ 13.837402] </TASK>
...
This patch adds a NULL check of "mp" before "write_metapage(mp)" is called.
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Zixuan Fu <r33s3n6@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Diffstat (limited to 'fs/jfs')
| -rw-r--r-- | fs/jfs/jfs_dmap.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index d8502f4989d9..e75f31b81d63 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -385,7 +385,8 @@ int dbFree(struct inode *ip, s64 blkno, s64 nblocks) } /* write the last buffer. */ - write_metapage(mp); + if (mp) + write_metapage(mp); IREAD_UNLOCK(ipbmap); |