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authorZixuan Fu <r33s3n6@gmail.com>2022-04-11 13:45:34 +0300
committerDave Kleikamp <dave.kleikamp@oracle.com>2022-04-19 18:20:51 +0300
commit0d4837fdb796f99369cf7691d33de1b856bcaf1f (patch)
treef6ca163b2a14ed2e152cf70458b1da8a125acecc /fs/jfs
parentb2d229d4ddb17db541098b83524d901257e93845 (diff)
downloadlinux-0d4837fdb796f99369cf7691d33de1b856bcaf1f.tar.xz
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.c3
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);