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Groups > linux.kernel > #1657240

[PATCH] ubifs: Fix a sleep-in-atomic bug in ubifs_read_nnode

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The driver may sleep under a spin lock, and the function call path is:
ubifs_change_lp (acquire the lock by spin_lock)
  change_category
    ubifs_remove_from_cat
      remove_from_lpt_heap
        dbg_check_heap
          ubifs_lpt_lookup
            ubifs_read_nnode
              kzalloc(GFP_NOFS) --> may sleep

To fix it, "GFP_NOFS" is replaced with "GFP_ATOMIC".

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
 fs/ubifs/lpt.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index 9a51710..4247934c 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -1205,7 +1205,7 @@ int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
 		lnum = c->lpt_lnum;
 		offs = c->lpt_offs;
 	}
-	nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
+	nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_ATOMIC);
 	if (!nnode) {
 		err = -ENOMEM;
 		goto out;
-- 
1.7.9.5

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[PATCH] ubifs: Fix a sleep-in-atomic bug in ubifs_read_nnode Jia-Ju Bai <baijiaju1990@163.com> - 2017-06-05 05:40 +0200
  Re: [PATCH] ubifs: Fix a sleep-in-atomic bug in ubifs_read_nnode Richard Weinberger <richard@nod.at> - 2017-06-05 10:30 +0200
    Re: [PATCH] ubifs: Fix a sleep-in-atomic bug in ubifs_read_nnode Richard Weinberger <richard@nod.at> - 2017-06-05 10:40 +0200
    Re: [PATCH] ubifs: Fix a sleep-in-atomic bug in ubifs_read_nnode Jia-Ju Bai <baijiaju1990@163.com> - 2017-06-05 10:50 +0200

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