The branch main has been updated by rmacklem:
URL:
https://cgit.FreeBSD.org/src/commit/?id=4046ad6bb0ee542a42d89a48a7d6a56564ed7f33
commit 4046ad6bb0ee542a42d89a48a7d6a56564ed7f33
Author: Rick Macklem <rmack...@freebsd.org>
AuthorDate: 2025-08-09 21:15:07 +0000
Commit: Rick Macklem <rmack...@freebsd.org>
CommitDate: 2025-08-09 21:16:18 +0000
vfs_syscalls.c: Fix handling of offset args for copy_file_range
Commit 197997a broke handling of the offset
arguments to copy_file_range() when specified non-NULL.
The code fails to update the offsets and, as such, a loop like:
do {
len = copy_file_range(infd, &inpos, outfd, &outpos,
SSIZE_MAX, 0);
} while (len > 0);
becomes an infinite loop, just doing the same copy over and
over again.
This patch fixes it.
The clause "(foffsets_locked || foffsets_set)" in the if is not
actually needed for correctness, but I thought it made the code
a little more readable and might avoid some static
analyzer from throwing a "used before being set" for
the savinoff and savoutoff variables.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D51845
MFC after: 2 weeks
Fixes: 197997a4c36d ("file: Fix offset handling in kern_copy_file_range()")
---
sys/kern/vfs_syscalls.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index c64618036733..b805e147bd62 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -5050,11 +5050,12 @@ kern_copy_file_range(struct thread *td, int infd, off_t
*inoffp, int outfd,
size_t retlen;
void *rl_rcookie, *rl_wcookie;
off_t inoff, outoff, savinoff, savoutoff;
- bool foffsets_locked;
+ bool foffsets_locked, foffsets_set;
infp = outfp = NULL;
rl_rcookie = rl_wcookie = NULL;
foffsets_locked = false;
+ foffsets_set = false;
error = 0;
retlen = 0;
@@ -5122,6 +5123,8 @@ kern_copy_file_range(struct thread *td, int infd, off_t
*inoffp, int outfd,
}
foffset_lock_pair(infp1, &inoff, outfp1, &outoff, 0);
foffsets_locked = true;
+ } else {
+ foffsets_set = true;
}
savinoff = inoff;
savoutoff = outoff;
@@ -5180,11 +5183,12 @@ out:
vn_rangelock_unlock(invp, rl_rcookie);
if (rl_wcookie != NULL)
vn_rangelock_unlock(outvp, rl_wcookie);
+ if ((foffsets_locked || foffsets_set) &&
+ (error == EINTR || error == ERESTART)) {
+ inoff = savinoff;
+ outoff = savoutoff;
+ }
if (foffsets_locked) {
- if (error == EINTR || error == ERESTART) {
- inoff = savinoff;
- outoff = savoutoff;
- }
if (inoffp == NULL)
foffset_unlock(infp, inoff, 0);
else
@@ -5193,6 +5197,9 @@ out:
foffset_unlock(outfp, outoff, 0);
else
*outoffp = outoff;
+ } else if (foffsets_set) {
+ *inoffp = inoff;
+ *outoffp = outoff;
}
if (outfp != NULL)
fdrop(outfp, td);
