From 164c24063a3eadee11b46575c5482b2f1417be49 Mon Sep 17 00:00:00 2001 From: Chen Jie Date: Tue, 10 Feb 2015 12:49:48 -0800 Subject: [PATCH] jffs2: fix handling of corrupted summary length sm->offset maybe wrong but magic maybe right, the offset do not have CRC. Badness at c00c7580 [verbose debug info unavailable] NIP: c00c7580 LR: c00c718c CTR: 00000014 REGS: df07bb40 TRAP: 0700 Not tainted (2.6.34.13-WR4.3.0.0_standard) MSR: 00029000 CR: 22084f84 XER: 00000000 TASK = df84d6e0[908] 'mount' THREAD: df07a000 GPR00: 00000001 df07bbf0 df84d6e0 00000000 00000001 00000000 df07bb58 00000041 GPR08: 00000041 c0638860 00000000 00000010 22084f88 100636c8 df814ff8 00000000 GPR16: df84d6e0 dfa558cc c05adb90 00000048 c0452d30 00000000 000240d0 000040d0 GPR24: 00000014 c05ae734 c05be2e0 00000000 00000001 00000000 00000000 c05ae730 NIP [c00c7580] __alloc_pages_nodemask+0x4d0/0x638 LR [c00c718c] __alloc_pages_nodemask+0xdc/0x638 Call Trace: [df07bbf0] [c00c718c] __alloc_pages_nodemask+0xdc/0x638 (unreliable) [df07bc90] [c00c7708] __get_free_pages+0x20/0x48 [df07bca0] [c00f4a40] __kmalloc+0x15c/0x1ec [df07bcd0] [c01fc880] jffs2_scan_medium+0xa58/0x14d0 [df07bd70] [c01ff38c] jffs2_do_mount_fs+0x1f4/0x6b4 [df07bdb0] [c020144c] jffs2_do_fill_super+0xa8/0x260 [df07bdd0] [c020230c] jffs2_fill_super+0x104/0x184 [df07be00] [c0335814] get_sb_mtd_aux+0x9c/0xec [df07be20] [c033596c] get_sb_mtd+0x84/0x1e8 [df07be60] [c0201ed0] jffs2_get_sb+0x1c/0x2c [df07be70] [c0103898] vfs_kern_mount+0x78/0x1e8 [df07bea0] [c0103a58] do_kern_mount+0x40/0x100 [df07bec0] [c011fe90] do_mount+0x240/0x890 [df07bf10] [c0120570] sys_mount+0x90/0xd8 [df07bf40] [c00110d8] ret_from_syscall+0x0/0x4 === Exception: c01 at 0xff61a34 LR = 0x100135f0 Instruction dump: 38800005 38600000 48010f41 4bfffe1c 4bfc2d15 4bfffe8c 72e90200 4082fc28 3d20c064 39298860 8809000d 68000001 <0f000000> 2f800000 419efc0c 38000001 mount: mounting /dev/mtdblock3 on /common failed: Input/output error Signed-off-by: Chen Jie Cc: Signed-off-by: Andrew Morton Signed-off-by: David Woodhouse --- fs/jffs2/scan.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/jffs2/scan.c b/fs/jffs2/scan.c index 7654e87b0428..9ad5ba4b299b 100644 --- a/fs/jffs2/scan.c +++ b/fs/jffs2/scan.c @@ -510,6 +510,10 @@ static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblo sumlen = c->sector_size - je32_to_cpu(sm->offset); sumptr = buf + buf_size - sumlen; + /* sm->offset maybe wrong but MAGIC maybe right */ + if (sumlen > c->sector_size) + goto full_scan; + /* Now, make sure the summary itself is available */ if (sumlen > buf_size) { /* Need to kmalloc for this. */ @@ -544,6 +548,7 @@ static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblo } } +full_scan: buf_ofs = jeb->offset; if (!buf_size) { -- 2.20.1