[PATCH 1/2] jffs2: Fix segmentation fault found in stress test

[PATCH 1/2] jffs2: Fix segmentation fault found in stress test

[Kamlakant Patel]

Creating a large file on a JFFS2 partition sometimes crashes with this call
trace:

[  306.476000] CPU 13 Unable to handle kernel paging request at virtual address c0000000dfff8002, epc == ffffffffc03a80a8, ra == ffffffffc03a8044
[  306.488000] Oops[#1]:
[  306.488000] Cpu 13
[  306.492000] $ 0   : 0000000000000000 0000000000000000 0000000000008008 0000000000008007
[  306.500000] $ 4   : c0000000dfff8002 000000000000009f c0000000e0007cde c0000000ee95fa58
[  306.508000] $ 8   : 0000000000000001 0000000000008008 0000000000010000 ffffffffffff8002
[  306.516000] $12   : 0000000000007fa9 000000000000ff0e 000000000000ff0f 80e55930aebb92bb
[  306.524000] $16   : c0000000e0000000 c0000000ee95fa5c c0000000efc80000 ffffffffc09edd70
[  306.532000] $20   : ffffffffc2b60000 c0000000ee95fa58 0000000000000000 c0000000efc80000
[  306.540000] $24   : 0000000000000000 0000000000000004
[  306.548000] $28   : c0000000ee950000 c0000000ee95f738 0000000000000000 ffffffffc03a8044
[  306.556000] Hi    : 00000000000574a5
[  306.560000] Lo    : 6193b7a7e903d8c9
[  306.564000] epc   : ffffffffc03a80a8 jffs2_rtime_compress+0x98/0x198
[  306.568000]     Tainted: G        W
[  306.572000] ra    : ffffffffc03a8044 jffs2_rtime_compress+0x34/0x198
[  306.580000] Status: 5000f8e3    KX SX UX KERNEL EXL IE
[  306.584000] Cause : 00800008
[  306.588000] BadVA : c0000000dfff8002
[  306.592000] PrId  : 000c1100 (Netlogic XLP)
[  306.596000] Modules linked in:
[  306.596000] Process dd (pid: 170, threadinfo=c0000000ee950000, task=c0000000ee6e0858, tls=0000000000c47490)
[  306.608000] Stack : 7c547f377ddc7ee4 7ffc7f967f5d7fae 7f617f507fc37ff4 7e7d7f817f487f5f
        7d8e7fec7ee87eb3 7e977ff27eec7f9e 7d677ec67f917f67 7f3d7e457f017ed7
        7fd37f517f867eb2 7fed7fd17ca57e1d 7e5f7fe87f257f77 7fd77f0d7ede7fdb
        7fba7fef7e197f99 7fde7fe07ee37eb5 7f5c7f8c7fc67f65 7f457fb87f847e93
        7f737f3e7d137cd9 7f8e7e9c7fc47d25 7dbb7fac7fb67e52 7ff17f627da97f64
        7f6b7df77ffa7ec5 80057ef17f357fb3 7f767fa27dfc7fd5 7fe37e8e7fd07e53
        7e227fcf7efb7fa1 7f547e787fa87fcc 7fcb7fc57f5a7ffb 7fc07f6c7ea97e80
        7e2d7ed17e587ee0 7fb17f9d7feb7f31 7f607e797e887faa 7f757fdd7c607ff3
        7e877e657ef37fbd 7ec17fd67fe67ff7 7ff67f797ff87dc4 7eef7f3a7c337fa6
        7fe57fc97ed87f4b 7ebe7f097f0b8003 7fe97e2a7d997cba 7f587f987f3c7fa9
        ...
[  306.676000] Call Trace:
[  306.680000] [<ffffffffc03a80a8>] jffs2_rtime_compress+0x98/0x198
[  306.684000] [<ffffffffc0394f10>] jffs2_selected_compress+0x110/0x230
[  306.692000] [<ffffffffc039508c>] jffs2_compress+0x5c/0x388
[  306.696000] [<ffffffffc039dc58>] jffs2_write_inode_range+0xd8/0x388
[  306.704000] [<ffffffffc03971bc>] jffs2_write_end+0x16c/0x2d0
[  306.708000] [<ffffffffc01d3d90>] generic_file_buffered_write+0xf8/0x2b8
[  306.716000] [<ffffffffc01d4e7c>] __generic_file_aio_write+0x1ac/0x350
[  306.720000] [<ffffffffc01d50a0>] generic_file_aio_write+0x80/0x168
[  306.728000] [<ffffffffc021f7dc>] do_sync_write+0x94/0xf8
[  306.732000] [<ffffffffc021ff6c>] vfs_write+0xa4/0x1a0
[  306.736000] [<ffffffffc02202e8>] SyS_write+0x50/0x90
[  306.744000] [<ffffffffc0116cc0>] handle_sys+0x180/0x1a0
[  306.748000]
[  306.748000]
Code: 020b202d  0205282d  90a50000 <90840000> 14a40038  00000000  0060602d  0000282d  016c5823
[  306.760000] ---[ end trace 79dd088435be02d0 ]---
Segmentation fault

This crash is caused because the 'positions' is declared as an array of signed
short. The value of position is in the range 0..65535, and will be converted
to a negative number when the position is greater than 32767 and causes a
corruption and crash. Changing the definition to 'unsigned short' fixes this
issue

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Signed-off-by: Kamlakant Patel <kamlakant.patel@broadcom.com>
---
 fs/jffs2/compr_rtime.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/jffs2/compr_rtime.c b/fs/jffs2/compr_rtime.c
index 16a5047..406d9cc 100644
--- a/fs/jffs2/compr_rtime.c
+++ b/fs/jffs2/compr_rtime.c
@@ -33,7 +33,7 @@ static int jffs2_rtime_compress(unsigned char *data_in,
 				unsigned char *cpage_out,
 				uint32_t *sourcelen, uint32_t *dstlen)
 {
-	short positions[256];
+	unsigned short positions[256];
 	int outpos = 0;
 	int pos=0;
 
@@ -74,7 +74,7 @@ static int jffs2_rtime_decompress(unsigned char *data_in,
 				  unsigned char *cpage_out,
 				  uint32_t srclen, uint32_t destlen)
 {
-	short positions[256];
+	unsigned short positions[256];
 	int outpos = 0;
 	int pos=0;
 
-- 
1.8.1.3

[PATCH 2/2] jffs2: Fix crash due to truncation of csize

[Kamlakant Patel]

From: Ajesh Kunhipurayil Vijayan <ajesh@broadcom.com>

mounting JFFS2 partition sometimes crashes with this call trace:

[ 1322.240000] Kernel bug detected[#1]:
[ 1322.244000] Cpu 2
[ 1322.244000] $ 0   : 0000000000000000 0000000000000018 000000003ff00070 0000000000000001
[ 1322.252000] $ 4   : 0000000000000000 c0000000f3980150 0000000000000000 0000000000010000
[ 1322.260000] $ 8   : ffffffffc09cd5f8 0000000000000001 0000000000000088 c0000000ed300de8
[ 1322.268000] $12   : e5e19d9c5f613a45 ffffffffc046d464 0000000000000000 66227ba5ea67b74e
[ 1322.276000] $16   : c0000000f1769c00 c0000000ed1e0200 c0000000f3980150 0000000000000000
[ 1322.284000] $20   : c0000000f3a80000 00000000fffffffc c0000000ed2cfbd8 c0000000f39818f0
[ 1322.292000] $24   : 0000000000000004 0000000000000000
[ 1322.300000] $28   : c0000000ed2c0000 c0000000ed2cfab8 0000000000010000 ffffffffc039c0b0
[ 1322.308000] Hi    : 000000000000023c
[ 1322.312000] Lo    : 000000000003f802
[ 1322.316000] epc   : ffffffffc039a9f8 check_tn_node+0x88/0x3b0
[ 1322.320000]     Not tainted
[ 1322.324000] ra    : ffffffffc039c0b0 jffs2_do_read_inode_internal+0x1250/0x1e48
[ 1322.332000] Status: 5400f8e3    KX SX UX KERNEL EXL IE
[ 1322.336000] Cause : 00800034
[ 1322.340000] PrId  : 000c1004 (Netlogic XLP)
[ 1322.344000] Modules linked in:
[ 1322.348000] Process jffs2_gcd_mtd7 (pid: 264, threadinfo=c0000000ed2c0000, task=c0000000f0e68dd8, tls=0000000000000000)
[ 1322.356000] Stack : c0000000f1769e30 c0000000ed010780 c0000000ed010780 c0000000ed300000
        c0000000f1769c00 c0000000f3980150 c0000000f3a80000 00000000fffffffc
        c0000000ed2cfbd8 ffffffffc039c0b0 ffffffffc09c6340 0000000000001000
        0000000000000dec ffffffffc016c9d8 c0000000f39805a0 c0000000f3980180
        0000008600000000 0000000000000000 0000000000000000 0000000000000000
        0001000000000dec c0000000f1769d98 c0000000ed2cfb18 0000000000010000
        0000000000010000 0000000000000044 c0000000f3a80000 c0000000f1769c00
        c0000000f3d207a8 c0000000f1769d98 c0000000f1769de0 ffffffffc076f9c0
        0000000000000009 0000000000000000 0000000000000000 ffffffffc039cf90
        0000000000000017 ffffffffc013fbdc 0000000000000001 000000010003e61c
        ...
[ 1322.424000] Call Trace:
[ 1322.428000] [<ffffffffc039a9f8>] check_tn_node+0x88/0x3b0
[ 1322.432000] [<ffffffffc039c0b0>] jffs2_do_read_inode_internal+0x1250/0x1e48
[ 1322.440000] [<ffffffffc039cf90>] jffs2_do_crccheck_inode+0x70/0xd0
[ 1322.448000] [<ffffffffc03a1b80>] jffs2_garbage_collect_pass+0x160/0x870
[ 1322.452000] [<ffffffffc03a392c>] jffs2_garbage_collect_thread+0xdc/0x1f0
[ 1322.460000] [<ffffffffc01541c8>] kthread+0xb8/0xc0
[ 1322.464000] [<ffffffffc0106d18>] kernel_thread_helper+0x10/0x18
[ 1322.472000]
[ 1322.472000]
Code: 67bd0050  94a4002c  2c830001 <00038036> de050218  2403fffc  0080a82d  00431824  24630044
[ 1322.480000] ---[ end trace b052bb90e97dfbf5 ]---

The variable csize in structure jffs2_tmp_dnode_info is of type uint16_t, but it
is used to hold the compressed data length(csize) which is declared as uint32_t.
So, when the value of csize exceeds 16bits, it gets truncated when assigned to
tn->csize. This is causing a kernel BUG.
Changing the definition of csize in jffs2_tmp_dnode_info to uint32_t fixes the issue.

Signed-off-by: Ajesh Kunhipurayil Vijayan <ajesh@broadcom.com>
Signed-off-by: Kamlakant Patel <kamlakant.patel@broadcom.com>
---
 fs/jffs2/nodelist.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/jffs2/nodelist.h b/fs/jffs2/nodelist.h
index e4619b0..fa35ff7 100644
--- a/fs/jffs2/nodelist.h
+++ b/fs/jffs2/nodelist.h
@@ -231,7 +231,7 @@ struct jffs2_tmp_dnode_info
 	uint32_t version;
 	uint32_t data_crc;
 	uint32_t partial_crc;
-	uint16_t csize;
+	uint32_t csize;
 	uint16_t overlapped;
 };
 
-- 
1.8.1.3

Re: [PATCH 1/2] jffs2: Fix segmentation fault found in stress test

[Brian Norris]

On Mon, Jan 06, 2014 at 07:06:54PM +0530, Kamlakant Patel wrote:
> Creating a large file on a JFFS2 partition sometimes crashes with this call
> trace:
[...]
> 
> This crash is caused because the 'positions' is declared as an array of signed
> short. The value of position is in the range 0..65535, and will be converted
> to a negative number when the position is greater than 32767 and causes a
> corruption and crash. Changing the definition to 'unsigned short' fixes this
> issue
> 
> Signed-off-by: Jayachandran C <jchandra@broadcom.com>
> Signed-off-by: Kamlakant Patel <kamlakant.patel@broadcom.com>

Pushed both patches to l2-mtd.git, and tagged them for -stable. Let me
know if you object.

Thanks,
Brian