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| author | Vasily Averin <vvs@virtuozzo.com> | 2020-01-25 12:10:02 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-01-27 12:54:32 +0300 |
| commit | 90435a7891a2259b0f74c5a1bc5600d0d64cba8f (patch) | |
| tree | dcaf37c1d2dd0a92827364fd29a3c1f783fe7ba0 /kernel/bpf/inode.c | |
| parent | 07fdbee134b3530ef30c709aa4251ca04ea9e3f8 (diff) | |
| download | linux-90435a7891a2259b0f74c5a1bc5600d0d64cba8f.tar.xz | |
bpf: map_seq_next should always increase position index
If seq_file .next fuction does not change position index,
read after some lseek can generate an unexpected output.
See also: https://bugzilla.kernel.org/show_bug.cgi?id=206283
v1 -> v2: removed missed increment in end of function
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/eca84fdd-c374-a154-d874-6c7b55fc3bc4@virtuozzo.com
Diffstat (limited to 'kernel/bpf/inode.c')
| -rw-r--r-- | kernel/bpf/inode.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index e11059b99f18..bd2fd8eab470 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -196,6 +196,7 @@ static void *map_seq_next(struct seq_file *m, void *v, loff_t *pos) void *key = map_iter(m)->key; void *prev_key; + (*pos)++; if (map_iter(m)->done) return NULL; @@ -208,8 +209,6 @@ static void *map_seq_next(struct seq_file *m, void *v, loff_t *pos) map_iter(m)->done = true; return NULL; } - - ++(*pos); return key; } |