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author | David S. Miller <davem@davemloft.net> | 2020-01-24 11:42:18 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2020-01-24 11:42:18 +0100 |
commit | 623c8d5c74c69a41573da5a38bb59e8652113f56 (patch) | |
tree | bad2d6a9c9497194acdbb3d35835b0c738d7973c /net/atm/proc.c | |
parent | 2bec445f9bf35e52e395b971df48d3e1e5dc704a (diff) | |
parent | 4fc427e0515811250647d44de38d87d7b0e0790f (diff) |
Merge branch 'netdev-seq_file-next-functions-should-increase-position-index'
Vasily Averin says:
====================
netdev: seq_file .next functions should increase position index
In Aug 2018 NeilBrown noticed
commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface")
"Some ->next functions do not increment *pos when they return NULL...
Note that such ->next functions are buggy and should be fixed.
A simple demonstration is
dd if=/proc/swaps bs=1000 skip=1
Choose any block size larger than the size of /proc/swaps. This will
always show the whole last line of /proc/swaps"
Described problem is still actual. If you make lseek into middle of last output line
following read will output end of last line and whole last line once again.
$ dd if=/proc/swaps bs=1 # usual output
Filename Type Size Used Priority
/dev/dm-0 partition 4194812 97536 -2
104+0 records in
104+0 records out
104 bytes copied
$ dd if=/proc/swaps bs=40 skip=1 # last line was generated twice
dd: /proc/swaps: cannot skip to specified offset
v/dm-0 partition 4194812 97536 -2
/dev/dm-0 partition 4194812 97536 -2
3+1 records in
3+1 records out
131 bytes copied
There are lot of other affected files, I've found 30+ including
/proc/net/ip_tables_matches and /proc/sysvipc/*
This patch-set fixes files related to netdev@
https://bugzilla.kernel.org/show_bug.cgi?id=206283
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/atm/proc.c')
-rw-r--r-- | net/atm/proc.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/atm/proc.c b/net/atm/proc.c index d79221fd4dae..c31896707313 100644 --- a/net/atm/proc.c +++ b/net/atm/proc.c @@ -134,8 +134,7 @@ static void vcc_seq_stop(struct seq_file *seq, void *v) static void *vcc_seq_next(struct seq_file *seq, void *v, loff_t *pos) { v = vcc_walk(seq, 1); - if (v) - (*pos)++; + (*pos)++; return v; } |