The memset() doesn't perform any NULL-pointer checking before dereferencing passed pointer so this should be checked before calling it. This fixes next issue: [38200.069122] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [38200.078002] pgd = c0004000 [38200.080963] [00000000] *pgd=00000000 [38200.084991] Internal error: Oops: 805 [#1] PREEMPT SMP ARM [38200.091003] Modules linked in: rproc_drm(O) tf_driver(O) gps_drv wl18xx(O) wl12xx(O) wlcore(O) mac80211(O) cfg80211(O) pvrsrvkm_sgx540_120(O) compat(O) [38200.106719] CPU: 1 Tainted: G W O (3.4.34 #1) [38200.112579] PC is at __memzero+0x24/0x80 [38200.116882] LR is at 0x0 [38200.119689] pc : [<c023b004>] lr : [<00000000>] psr: 28000113 [38200.119689] sp : d66b1e2c ip : 00000000 fp : d66b1e54 [38200.132171] r10: 00000000 r9 : d6ad48c0 r8 : c01bd414 [38200.137847] r7 : 00000000 r6 : ffffffff r5 : cb19fe48 r4 : d678bc00 [38200.144958] r3 : 00000000 r2 : 00000000 r1 : 00000fc0 r0 : 00000000 [38200.152008] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel [38200.160034] Control: 10c5387d Table: 967b004a DAC: 00000015 [...] [38200.888031] Backtrace: [38200.890869] [<c01c509c>] (jbd2_journal_get_descriptor_buffer+0x0/0xa4) from [<c01bddf0>] (jbd2_journal_commit_transaction+0x994/0x18f4) [38200.903930] r5:d6ad5348 r4:d678bc00 [38200.907989] [<c01bd45c>] (jbd2_journal_commit_transaction+0x0/0x18f4) from [<c01c2e70>] (kjournald2+0xb4/0x24c) [38200.918884] [<c01c2dbc>] (kjournald2+0x0/0x24c) from [<c0066990>] (kthread+0x90/0x9c) [38200.927429] [<c0066900>] (kthread+0x0/0x9c) from [<c004a968>] (do_exit+0x0/0x804) [38200.935577] r6:c004a968 r5:c0066900 r4:d6749c8c [38200.940887] Code: e52de004 e1a0c002 e1a0e002 e2511040 (a8a0500c) Signed-off-by: Ruslan Bilovol <ruslan.bilovol@xxxxxx> --- fs/jbd2/journal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 9545757..48f3da5 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -810,7 +810,7 @@ struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal) return NULL; bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); - if (!bh) + if (!bh || !bh->b_data) return NULL; lock_buffer(bh); memset(bh->b_data, 0, journal->j_blocksize); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
