From 16f048c13af87e67a5d8afc42dc16754907696b6 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Fri, 8 Jan 2021 16:08:43 +0100 Subject: [PATCH] BUG/MINOR: sample: fix concat() converter's corruption with non-string variables Patrick Hemmer reported that calling concat() with an integer variable causes a %00 to appear at the beginning of the output. Looking at the code, it's not surprising. The function uses get_trash_chunk() to get one of the trashes, but can call casting functions which will also use their trash in turn and will cycle back to ours, causing the trash to be overwritten before being assigned to a sample. By allocating the trash from a pool using alloc_trash_chunk(), we can avoid this. However we must free it so the trash's contents must be moved to a permanent trash buffer before returning. This is what's achieved using smp_dup(). This should be backported as far as 2.0. (cherry picked from commit 591fc3a330005c289b4705fe4cb37c4eec9f9eed) Signed-off-by: Willy Tarreau (cherry picked from commit 79f4360bcbf4d4c4a56b7688dbb2cea839a5b9ba) Signed-off-by: Willy Tarreau (cherry picked from commit 3d8ff18aaa8046d3e64a94d33c180db88c8033a0) Signed-off-by: Willy Tarreau --- src/sample.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/sample.c b/src/sample.c index 31b2274..e38a98e 100644 --- a/src/sample.c +++ b/src/sample.c @@ -2750,7 +2750,7 @@ static int sample_conv_concat(const struct arg *arg_p, struct sample *smp, void struct sample tmp; int max; - trash = get_trash_chunk(); + trash = alloc_trash_chunk(); trash->data = smp->data.u.str.data; if (trash->data > trash->size - 1) trash->data = trash->size - 1; @@ -2802,6 +2802,8 @@ static int sample_conv_concat(const struct arg *arg_p, struct sample *smp, void smp->data.u.str = *trash; smp->data.type = SMP_T_STR; + smp_dup(smp); + free_trash_chunk(trash); return 1; } -- 1.7.10.4