| Message ID | 20220914100812.1414768-3-yebin10@huawei.com |
|---|---|
| State | Awaiting Upstream |
| Headers | show |
| Series | Fix two issue in jbd2_fc_wait_bufs | expand |
On Wed 14-09-22 18:08:12, Ye Bin wrote: > In 'jbd2_fc_wait_bufs' use 'bh' after put buffer head reference count > which may lead to use-after-free. > So judge buffer if uptodate before put buffer head reference count. > > Signed-off-by: Ye Bin <yebin10@huawei.com> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/jbd2/journal.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > index 1c833d8cb0fe..4d49f629d06b 100644 > --- a/fs/jbd2/journal.c > +++ b/fs/jbd2/journal.c > @@ -923,16 +923,16 @@ int jbd2_fc_wait_bufs(journal_t *journal, int num_blks) > for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) { > bh = journal->j_fc_wbuf[i]; > wait_on_buffer(bh); > - put_bh(bh); > - journal->j_fc_wbuf[i] = NULL; > /* > * Update j_fc_off so jbd2_fc_release_bufs can release remain > * buffer head. > */ > if (unlikely(!buffer_uptodate(bh))) { > - journal->j_fc_off = i; > + journal->j_fc_off = i + 1; > return -EIO; > } > + put_bh(bh); > + journal->j_fc_wbuf[i] = NULL; > } > > return 0; > -- > 2.31.1 >
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 1c833d8cb0fe..4d49f629d06b 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -923,16 +923,16 @@ int jbd2_fc_wait_bufs(journal_t *journal, int num_blks) for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) { bh = journal->j_fc_wbuf[i]; wait_on_buffer(bh); - put_bh(bh); - journal->j_fc_wbuf[i] = NULL; /* * Update j_fc_off so jbd2_fc_release_bufs can release remain * buffer head. */ if (unlikely(!buffer_uptodate(bh))) { - journal->j_fc_off = i; + journal->j_fc_off = i + 1; return -EIO; } + put_bh(bh); + journal->j_fc_wbuf[i] = NULL; } return 0;
In 'jbd2_fc_wait_bufs' use 'bh' after put buffer head reference count which may lead to use-after-free. So judge buffer if uptodate before put buffer head reference count. Signed-off-by: Ye Bin <yebin10@huawei.com> --- fs/jbd2/journal.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)