git: 7441705cae68 - stable/14 - tail: Fix heap overflow in -F case.
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Date: Wed, 13 Dec 2023 20:07:06 UTC
The branch stable/14 has been updated by des:
URL: https://cgit.FreeBSD.org/src/commit/?id=7441705cae6887332b408c04c479e616403d3739
commit 7441705cae6887332b408c04c479e616403d3739
Author: Dag-Erling Smørgrav <des@FreeBSD.org>
AuthorDate: 2023-11-29 21:48:50 +0000
Commit: Dag-Erling Smørgrav <des@FreeBSD.org>
CommitDate: 2023-12-13 16:41:48 +0000
tail: Fix heap overflow in -F case.
The number of events we track can vary over time, but we only allocate
enough space for the exact number of events we are tracking when we
first begin, resulting in a trivially reproducable heap overflow. Fix
this by allocating enough space for the greatest possible number of
events (two per file) and clean up the code a bit.
Also add a test case which triggers the aforementioned heap overflow,
although we don't currently have a way to detect it.
MFC after: 1 week
Sponsored by: Klara, Inc.
Reviewed by: allanjude, markj
Differential Revision: https://reviews.freebsd.org/D42839
(cherry picked from commit 621f45532c5887c96b708ce232c52878d0053325)
tail: Clean up error messages.
MFC after: 1 week
Sponsored by: Klara, Inc.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D42842
(cherry picked from commit b70e57be2cfe83ec9f410e2f317ea38aaac61a98)
---
usr.bin/tail/forward.c | 39 ++++++++++++++++++---------------------
usr.bin/tail/read.c | 8 ++++----
usr.bin/tail/reverse.c | 2 +-
usr.bin/tail/tail.c | 6 +++---
usr.bin/tail/tests/tail_test.sh | 21 ++++++++++++++++++++-
5 files changed, 46 insertions(+), 30 deletions(-)
diff --git a/usr.bin/tail/forward.c b/usr.bin/tail/forward.c
index e2a3eb77aade..a0f66262608a 100644
--- a/usr.bin/tail/forward.c
+++ b/usr.bin/tail/forward.c
@@ -275,7 +275,7 @@ set_events(file_info_t *files)
action = USE_KQUEUE;
for (i = 0, file = files; i < no_files; i++, file++) {
- if (! file->fp)
+ if (!file->fp)
continue;
if (fstatfs(fileno(file->fp), &sf) == 0 &&
@@ -307,27 +307,21 @@ set_events(file_info_t *files)
void
follow(file_info_t *files, enum STYLE style, off_t off)
{
- int active, ev_change, i, n = -1;
+ int active, ev_change, i, n;
struct stat sb2;
file_info_t *file;
FILE *ftmp;
struct timespec ts;
/* Position each of the files */
-
- file = files;
active = 0;
- n = 0;
- for (i = 0; i < no_files; i++, file++) {
- if (file->fp) {
- active = 1;
- n++;
- if (vflag || (qflag == 0 && no_files > 1))
- printfn(file->file_name, 1);
- forward(file->fp, file->file_name, style, off, &file->st);
- if (Fflag && fileno(file->fp) != STDIN_FILENO)
- n++;
- }
+ for (i = 0, file = files; i < no_files; i++, file++) {
+ if (!file->fp)
+ continue;
+ active = 1;
+ if (vflag || (qflag == 0 && no_files > 1))
+ printfn(file->file_name, 1);
+ forward(file->fp, file->file_name, style, off, &file->st);
}
if (!Fflag && !active)
return;
@@ -337,9 +331,14 @@ follow(file_info_t *files, enum STYLE style, off_t off)
kq = kqueue();
if (kq < 0)
err(1, "kqueue");
- ev = malloc(n * sizeof(struct kevent));
- if (! ev)
- err(1, "Couldn't allocate memory for kevents.");
+ /*
+ * The number of kqueue events we track may vary over time and may
+ * even grow past its initial value in the -F case, but it will
+ * never exceed two per file, so just preallocate that.
+ */
+ ev = malloc(no_files * 2 * sizeof(struct kevent));
+ if (ev == NULL)
+ err(1, "failed to allocate memory for kevents");
set_events(files);
for (;;) {
@@ -413,9 +412,7 @@ follow(file_info_t *files, enum STYLE style, off_t off)
*/
do {
n = kevent(kq, NULL, 0, ev, 1, Fflag ? &ts : NULL);
- if (n < 0 && errno == EINTR)
- continue;
- if (n < 0)
+ if (n < 0 && errno != EINTR)
err(1, "kevent");
} while (n < 0);
if (n == 0) {
diff --git a/usr.bin/tail/read.c b/usr.bin/tail/read.c
index ff025b31d64c..67bc5750cd0b 100644
--- a/usr.bin/tail/read.c
+++ b/usr.bin/tail/read.c
@@ -72,7 +72,7 @@ bytes(FILE *fp, const char *fn, off_t off)
char *sp;
if ((sp = p = malloc(off)) == NULL)
- err(1, "malloc");
+ err(1, "failed to allocate memory");
for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF;) {
*p = ch;
@@ -146,7 +146,7 @@ lines(FILE *fp, const char *fn, off_t off)
int blen, cnt, recno, wrap;
if ((llines = calloc(off, sizeof(*llines))) == NULL)
- err(1, "calloc");
+ err(1, "failed to allocate memory");
p = sp = NULL;
blen = cnt = recno = wrap = 0;
rc = 0;
@@ -154,7 +154,7 @@ lines(FILE *fp, const char *fn, off_t off)
while ((ch = getc(fp)) != EOF) {
if (++cnt > blen) {
if ((sp = realloc(sp, blen += 1024)) == NULL)
- err(1, "realloc");
+ err(1, "failed to allocate memory");
p = sp + cnt - 1;
}
*p++ = ch;
@@ -163,7 +163,7 @@ lines(FILE *fp, const char *fn, off_t off)
llines[recno].blen = cnt + 256;
if ((llines[recno].l = realloc(llines[recno].l,
llines[recno].blen)) == NULL)
- err(1, "realloc");
+ err(1, "failed to allocate memory");
}
bcopy(sp, llines[recno].l, llines[recno].len = cnt);
cnt = 0;
diff --git a/usr.bin/tail/reverse.c b/usr.bin/tail/reverse.c
index 12231530e679..67d27d487d1c 100644
--- a/usr.bin/tail/reverse.c
+++ b/usr.bin/tail/reverse.c
@@ -212,7 +212,7 @@ r_buf(FILE *fp, const char *fn)
while ((tl = malloc(sizeof(bfelem_t))) == NULL) {
first = TAILQ_FIRST(&head);
if (TAILQ_EMPTY(&head))
- err(1, "malloc");
+ err(1, "failed to allocate memory");
enomem += first->len;
TAILQ_REMOVE(&head, first, entries);
free(first);
diff --git a/usr.bin/tail/tail.c b/usr.bin/tail/tail.c
index 492a6494628d..c206b11863a5 100644
--- a/usr.bin/tail/tail.c
+++ b/usr.bin/tail/tail.c
@@ -173,7 +173,7 @@ main(int argc, char *argv[])
cap_rights_set(&rights, CAP_EVENT);
if (caph_rights_limit(STDIN_FILENO, &rights) < 0 ||
caph_limit_stderr() < 0 || caph_limit_stdout() < 0)
- err(1, "can't limit stdio rights");
+ err(1, "unable to limit stdio rights");
fa = fileargs_init(argc, argv, O_RDONLY, 0, &rights, FA_OPEN);
if (fa == NULL)
@@ -213,7 +213,7 @@ main(int argc, char *argv[])
if (*argv && fflag) {
files = malloc(no_files * sizeof(struct file_info));
if (files == NULL)
- err(1, "Couldn't malloc space for file descriptors.");
+ err(1, "failed to allocate memory for file descriptors");
for (filep = files; (fn = *argv++); filep++) {
filep->file_name = fn;
@@ -308,7 +308,7 @@ obsolete(char *argv[])
/* Malloc space for dash, new option and argument. */
len = strlen(*argv);
if ((start = p = malloc(len + 3)) == NULL)
- err(1, "malloc");
+ err(1, "failed to allocate memory");
*p++ = '-';
/*
diff --git a/usr.bin/tail/tests/tail_test.sh b/usr.bin/tail/tests/tail_test.sh
index 8123a310fe67..9c941f8a2c2f 100755
--- a/usr.bin/tail/tests/tail_test.sh
+++ b/usr.bin/tail/tests/tail_test.sh
@@ -329,10 +329,28 @@ follow_stdin_body()
atf_check kill $pid
}
+atf_test_case follow_create
+follow_create_head()
+{
+ atf_set "descr" "Verify that -F works when a file is created"
+}
+follow_create_body()
+{
+ local pid
+
+ rm -f infile
+ tail -F infile > outfile &
+ pid=$!
+ seq 1 5 >infile
+ sleep 2
+ atf_check cmp infile outfile
+ atf_check kill $pid
+}
+
atf_test_case follow_rename
follow_rename_head()
{
- atf_set "descr" "Verify that -F works"
+ atf_set "descr" "Verify that -F works when a file is replaced"
}
follow_rename_body()
{
@@ -424,6 +442,7 @@ atf_init_test_cases()
atf_add_test_case stdin
atf_add_test_case follow
atf_add_test_case follow_stdin
+ atf_add_test_case follow_create
atf_add_test_case follow_rename
atf_add_test_case silent_header
atf_add_test_case verbose_header