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authorMike Kravetz <mike.kravetz@oracle.com>2017-03-31 15:12:07 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-17 21:55:15 +0100
commit30a2ae50aef84ce6bb6132859a04dca461dbafdd (patch)
tree4e22efb21b9fd08323ee570e536233830585deb3
parent954648ebf8e27fcbf23b7954b79a22a5cacc83b1 (diff)
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mm/hugetlb.c: don't call region_abort if region_chg fails
commit ff8c0c53c47530ffea82c22a0a6df6332b56c957 upstream. Changes to hugetlbfs reservation maps is a two step process. The first step is a call to region_chg to determine what needs to be changed, and prepare that change. This should be followed by a call to call to region_add to commit the change, or region_abort to abort the change. The error path in hugetlb_reserve_pages called region_abort after a failed call to region_chg. As a result, the adds_in_progress counter in the reservation map is off by 1. This is caught by a VM_BUG_ON in resv_map_release when the reservation map is freed. syzkaller fuzzer (when using an injected kmalloc failure) found this bug, that resulted in the following: kernel BUG at mm/hugetlb.c:742! Call Trace: hugetlbfs_evict_inode+0x7b/0xa0 fs/hugetlbfs/inode.c:493 evict+0x481/0x920 fs/inode.c:553 iput_final fs/inode.c:1515 [inline] iput+0x62b/0xa20 fs/inode.c:1542 hugetlb_file_setup+0x593/0x9f0 fs/hugetlbfs/inode.c:1306 newseg+0x422/0xd30 ipc/shm.c:575 ipcget_new ipc/util.c:285 [inline] ipcget+0x21e/0x580 ipc/util.c:639 SYSC_shmget ipc/shm.c:673 [inline] SyS_shmget+0x158/0x230 ipc/shm.c:657 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: resv_map_release+0x265/0x330 mm/hugetlb.c:742 Link: http://lkml.kernel.org/r/1490821682-23228-1-git-send-email-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/hugetlb.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6f99a0f906bb..591e297f0ace 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4142,7 +4142,9 @@ int hugetlb_reserve_pages(struct inode *inode,
return 0;
out_err:
if (!vma || vma->vm_flags & VM_MAYSHARE)
- region_abort(resv_map, from, to);
+ /* Don't call region_abort if region_chg failed */
+ if (chg >= 0)
+ region_abort(resv_map, from, to);
if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER))
kref_put(&resv_map->refs, resv_map_release);
return ret;