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author | Theodore Ts'o <tytso@mit.edu> | 2018-04-18 18:49:31 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-02 17:59:53 +0300 |
commit | d0800f61b95703d09607217ad4d5775c5313429b (patch) | |
tree | 58c1e6c1bab1ebc8ae6fa332b3727766bb605372 /Documentation/s390/Debugging390.txt | |
parent | 754ca08efd83eeb9cccdb109da2fa0b3a27c1172 (diff) | |
download | linux-d0800f61b95703d09607217ad4d5775c5313429b.tar.xz |
ext4: set h_journal if there is a failure starting a reserved handle
commit b2569260d55228b617bd82aba6d0db2faeeb4116 upstream.
If ext4 tries to start a reserved handle via
jbd2_journal_start_reserved(), and the journal has been aborted, this
can result in a NULL pointer dereference. This is because the fields
h_journal and h_transaction in the handle structure share the same
memory, via a union, so jbd2_journal_start_reserved() will clear
h_journal before calling start_this_handle(). If this function fails
due to an aborted handle, h_journal will still be NULL, and the call
to jbd2_journal_free_reserved() will pass a NULL journal to
sub_reserve_credits().
This can be reproduced by running "kvm-xfstests -c dioread_nolock
generic/475".
Cc: stable@kernel.org # 3.11
Fixes: 8f7d89f36829b ("jbd2: transaction reservation support")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/s390/Debugging390.txt')
0 files changed, 0 insertions, 0 deletions