neovim/22780.patch
Andreas Schneider 86d3469aa8 Fix snprintf buffer overflow
resolves: rhbz#2165805
2023-04-06 11:16:04 +02:00

158 lines
5.6 KiB
Diff

From a4640cc51fda6b5688c9b79c2d4d7d19e6d758a3 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn@cryptomilk.org>
Date: Sat, 25 Mar 2023 11:26:36 +0100
Subject: [PATCH] fix: snprintf buffer overflow detected by -D_FORTIFY_SOURCE=3
Thread no. 1 (24 frames)
#8 snprintf at /usr/include/bits/stdio2.h:54
#9 set_cmdarg at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/eval.c:7044
#10 apply_autocmds_group at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/autocmd.c:1843
#11 apply_autocmds_exarg at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/autocmd.c:1549
#12 readfile at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/fileio.c:617
#13 buf_reload at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/fileio.c:5038
#14 buf_check_timestamp at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/fileio.c:4952
#15 check_timestamps at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/fileio.c:4678
#16 ex_checktime at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_cmds2.c:765
#17 execute_cmd0 at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:1620
#18 do_one_cmd at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:2275
#19 do_cmdline at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:584
#20 ex_execute at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/eval.c:7727
#21 execute_cmd0 at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:1620
#22 do_one_cmd at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:2275
#23 do_cmdline at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:584
#24 do_ucmd at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/usercmd.c:1661
#25 execute_cmd0 at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:1612
#26 do_one_cmd at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:2275
#27 do_cmdline at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/ex_docmd.c:584
#28 nv_colon at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/normal.c:4058
#29 normal_execute at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/normal.c:1172
#30 state_enter at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/state.c:88
#31 normal_enter at /usr/src/debug/neovim-0.8.2-2.fc38.x86_64/src/nvim/normal.c:471
Signed-off-by: Andreas Schneider <asn@cryptomilk.org>
---
src/nvim/eval.c | 73 +++++++++++++++++++++++++++++++++++++------------
1 file changed, 55 insertions(+), 18 deletions(-)
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index cd76d1108..c652d9507 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -6999,20 +6999,18 @@ char *set_cmdarg(exarg_T *eap, char *oldarg)
{
char *oldval = vimvars[VV_CMDARG].vv_str;
if (eap == NULL) {
- xfree(oldval);
- vimvars[VV_CMDARG].vv_str = oldarg;
- return NULL;
+ goto error;
}
size_t len = 0;
if (eap->force_bin == FORCE_BIN) {
- len = 6;
+ len += 6; // " ++bin"
} else if (eap->force_bin == FORCE_NOBIN) {
- len = 8;
+ len += 8; // " ++nobin"
}
if (eap->read_edit) {
- len += 7;
+ len += 7; // " ++edit"
}
if (eap->force_ff != 0) {
@@ -7027,38 +7025,77 @@ char *set_cmdarg(exarg_T *eap, char *oldarg)
const size_t newval_len = len + 1;
char *newval = xmalloc(newval_len);
+ size_t xlen = 0;
+ int rc = 0;
if (eap->force_bin == FORCE_BIN) {
- snprintf(newval, newval_len, " ++bin");
+ rc = snprintf(newval, newval_len, " ++bin");
} else if (eap->force_bin == FORCE_NOBIN) {
- snprintf(newval, newval_len, " ++nobin");
+ rc = snprintf(newval, newval_len, " ++nobin");
} else {
*newval = NUL;
}
+ if (rc < 0) {
+ goto error;
+ }
+ xlen += (size_t)rc;
if (eap->read_edit) {
- STRCAT(newval, " ++edit");
+ rc = snprintf(newval + xlen, newval_len - xlen, " ++edit");
+ if (rc < 0) {
+ goto error;
+ }
+ xlen += (size_t)rc;
}
if (eap->force_ff != 0) {
- snprintf(newval + strlen(newval), newval_len, " ++ff=%s",
- eap->force_ff == 'u' ? "unix" :
- eap->force_ff == 'd' ? "dos" : "mac");
+ rc = snprintf(newval + xlen,
+ newval_len - xlen,
+ " ++ff=%s",
+ eap->force_ff == 'u' ? "unix"
+ : eap->force_ff == 'd' ? "dos" : "mac");
+ if (rc < 0) {
+ goto error;
+ }
+ xlen += (size_t)rc;
}
if (eap->force_enc != 0) {
- snprintf(newval + strlen(newval), newval_len, " ++enc=%s",
- eap->cmd + eap->force_enc);
+ rc = snprintf(newval + (xlen), newval_len - xlen, " ++enc=%s", eap->cmd + eap->force_enc);
+ if (rc < 0) {
+ goto error;
+ }
+ xlen += (size_t)rc;
}
+
if (eap->bad_char == BAD_KEEP) {
- STRCPY(newval + strlen(newval), " ++bad=keep");
+ rc = snprintf(newval + xlen, newval_len - xlen, " ++bad=keep");
+ if (rc < 0) {
+ goto error;
+ }
+ xlen += (size_t)rc;
} else if (eap->bad_char == BAD_DROP) {
- STRCPY(newval + strlen(newval), " ++bad=drop");
+ rc = snprintf(newval + xlen, newval_len - xlen, " ++bad=drop");
+ if (rc < 0) {
+ goto error;
+ }
+ xlen += (size_t)rc;
} else if (eap->bad_char != 0) {
- snprintf(newval + strlen(newval), newval_len, " ++bad=%c",
- eap->bad_char);
+ rc = snprintf(newval + xlen, newval_len - xlen, " ++bad=%c", eap->bad_char);
+ if (rc < 0) {
+ goto error;
+ }
+ xlen += (size_t)rc;
}
+
+ assert(xlen <= newval_len);
+
vimvars[VV_CMDARG].vv_str = newval;
return oldval;
+
+error:
+ xfree(oldval);
+ vimvars[VV_CMDARG].vv_str = oldarg;
+ return NULL;
}
/// Check if variable "name[len]" is a local variable or an argument.
--
2.39.2